Auxilia

Italic text

Auxiliaries (from Latin: auxilia = "supports") formed the standing non-citizen corps of the Roman army of the Principate (30 BC - 284 AD), alongside the citizen legions. By the 2nd century, the auxilia contained the same number of infantry as the legions and in addition provided almost all the Roman army's cavalry and more specialised troops (especially light cavalry and archers). The auxilia thus represented nearly two-thirds of Rome's regular land forces at that time.Template:Hcref

Auxiliary troops were mainly recruited from the peregrini i.e. free provincial subjects of the Roman Empire who were not Roman citizens, the vast majority of the empire's population in the 1st and 2nd centuries.Template:Hcref Auxiliaries also recruited Roman citizens and barbarians (barbari, as the Romans called peoples located outside the Empire's borders). This was in contrast to the legions, which admitted Roman citizens only.

The auxilia developed from the varied contingents of non-Italian troops, especially cavalry, that the Roman Republic used in increasing numbers to support its legions after 200 BC. The Julio-Claudian period (30 BC-68 AD) saw the transformation of these motley temporary levies into a standing corps of regiments with standardised structure, equipment and conditions of service. By the end of this period, there were no significant differences between legionaries and most auxiliaries in terms of training, equipment, or combat capability.

Auxiliary regiments were often stationed in provinces other than the province in which they were originally raised. The regimental names of many auxiliary units persisted into the 4th century, but by then the units in question were different in size, structure, and quality from their predecessors.

Historical development

Roman Republic (to 30 BC)

Roman auxiliary infantry crossing a river, probably the Danube, on a pontoon bridge during the Dacian Wars (101-6 AD). They can be distinguished from legionaries by their oval shields. Trajan's Column, Rome

The core of the Roman fighting machine was the legion, which had evolved over centuries into a heavy infantry unit that was virtually invincible in close-quarter engagements on suitable ground. But the legion had a number of deficiencies, especially a lack of cavalry. Around 200 BC, a legion of 4,200 infantry had a cavalry arm of only 300 horse. This was because the class of citizens who could afford to pay for their own horse and equipment- the equestrian order, the second rank in Roman society, after the senatorial order- was small. In addition the legion lacked missile forces such as slingers and archers.

Until 200 BC, the bulk of a Roman army's cavalry was provided by Rome's regular Italian allies (socii), commonly known as the "Latin" allies, which made up the Roman military confederacy.Template:Hcref The confederacy was Rome's defence system until the Social War of 91-88 BC. The Latin forces were the closest equivalent in the Republic to the later Augustan auxilia (and their probable inspiration): a non-citizen corps of troops organised and equipped to legionary standards, of roughly the same numbers as the legions, but providing most of the cavalry.

The Latin forces were organised into alae (literally: "wings", because they were always posted on the flanks of the Roman line of battle). An allied ala, commanded by three Roman praefecti sociorum, was similar in infantry size to a legion, but contained a more substantial cavalry contingent: 900 horse, three times the legionary contingent. Since a pre-Social War consular army always contained an equal number of legions and alae, 75% of its cavalry was provided by the Latin allies. The overall cavalry element, however, remained modest: a normal consular army of two legions and two alae contained 16,800 infantry and only 2,400 cavalry (13% of the total force).

The Roman/Latin cavalry was sufficient while Rome was in conflict with other states in the mountainous Italian peninsula, which also disposed of limited cavalry resources. But as Rome was confronted by enemies that deployed far more powerful cavalry elements, the Roman deficiency in cavalry resulted in heavy defeats. The dangers were shown during the sporadic major invasions of Italy by the Gauls, and the expedition of the Greek king Pyrrhus of Epirus (275 BC). The decisive turning point was the Second Punic War (218-202 BC). Hannibal's major victories at the Trebia and at Cannae, were owed to his Spanish and Gallic heavy cavalry, which far outnumbered the Roman and Latin levies, and to his Numidians, light, fast cavalry which the Romans wholly lacked.Template:Hcref The decisive Roman victory at Zama in 202 BC, which ended the war, owed much to the Numidian cavalry provided by king Massinissa, which outnumbered the Roman/Latin cavalry fielded by 2 to 1.Template:Hcref From then, Roman armies were always accompanied by large numbers of non-Italian cavalry: Numidian light cavalry and, later, Gallic heavy cavalry. For example, Caesar relied heavily on Gallic and German cavalry for his Conquest of Gaul (58-51 BC).

As the role of native cavalry grew, that of Roman/Latin cavalry diminished. In the early 1st century BC, Roman cavalry was phased out altogether. After the Social War, the socii were all granted Roman citizenship, the Latin alae abolished, and the socii recruited into the legions. Furthermore, Roman equestrians were no longer required to perform cavalry service after this time. The late Republican legion was thus wholly bereft of cavalry. Template:Hcref

By the outbreak of the Second Punic War, the Romans were remedying the legion's other deficiencies by using non-Italian specialised troops. Livy reports Hiero of Syracuse offering to supply Rome with archers and slingers in 217 BC. From 200 BC onwards, specialist troops were hired as mercenaries on a regular basis: sagittarii (archers) from Crete, and funditores (slingers) from the Balearic Isles almost always accompanied Roman legions in campaigns all over the Mediterranean.

The main other sources of non-Italian troops in the late Republic were subject provincials, allied cities and Rome's amici (satellite kings). During the late Republic, non-Italian units were led by their own native chiefs, and their internal organisation was left to their own commanders. The units varied widely in dress, equipment, and weapons. They were normally raised for specific campaigns and often disbanded soon afterwards.

Rule of Augustus (30 BC-14 AD)

Legionary foot soldier wielding a gladius, a sword design invented by the Iberian people of pre-Roman Spain. The example shown is of the "Pompeii" type, used from the later 1st century onwards. Thus was a shorter (median blade length: 460mm) stabbing-and-slashing sword designed for close combat. On his left hip is just visible his pugio (dagger). The soldier is wearing a chain mail cuirass (lorica hamata) and an "imperial Gallic" type helmet, also prevalent in the late 1st century. He is leaning on his curved rectangular shield (scutum). The armour and weapons of an auxiliary infantryman were identical except that he carried an oval shield (clipeus)

At the end of the civil war period (30 BC), it appears that not all indigenous units were disbanded. Some of the more experienced units were kept in being to complement the legions, and became the core of the standing auxiliary forces that developed in the Julio-Claudian period. During the early rule of Augustus (30 BC onwards), the corps of regular auxilia was created. It was clearly inspired by the Latin forces of the pre-Social War Republic, as a corps of non-citizen troops parallel to the legions. But there were fundamental differences, the same as between Republican and Augustan legions. The Latin forces of the Republic were made up of part-time conscripts in units that would be raised and disbanded for and after particular campaigns. The Augustan auxilia were all-volunteer professionals serving in permanent units.

The unit structure of the auxilia also differed from the Latin alae, which were like legions with a larger cavalry arm. Augustus however organised the auxilia into regiments the size of cohorts (a tenth the size of legions), due to the much greater flexibility of the smaller unit size.Template:HcrefFurther, the regiments were of three types: ala (cavalry), cohors (infantry) and cohors equitata (mixed cavalry/infantry).

The evidence for the size of the Augustus' new units is not clearcut, with our most precise evidence dating to the 2nd century, by which time the unit strengths may have changed. Cohortes were likely modelled on legionary cohorts i.e. 6 centuriae of c80 men each (total c480 men). Alae were divided into turmae (squadrons) of c30 men, each under a decurio. (Literally: "leader of ten", a title which derives from the old Roman cavalry of the pre-Social War republic. This was divided into turmae, each under the command of 3 decuriones. The old title was retained, even though the officer now commanded 30 men). Cohortes equitatae were simply infantry cohortes with a cavalry contingent of 4 turmae added.

Auxiliary regiments were now led by a praefectus, who could be either (i) a native nobleman, who would probably be granted Roman citizenship for the purpose (e.g. the famous German war leader Arminius gained Roman citizenship probably by serving as an auxiliary prefect before turning against Rome); or (ii) a Roman, either of equestrian rank, or a senior centurion.

At the start of Augustus' sole rule (30BC), the original core auxiliary units in the West were composed of warlike tribesmen from the Gallic provinces (especially Gallia Belgica, which then included the regions later separated to form the provinces Germania Inferior and Germania Superior), and from Illyricum. By 19BC, the Cantabrian and Asturian Wars were concluded, leading to the annexation of northern Hispania and Lusitania. Judging by the names of attested auxiliary regiments, these parts of the Iberian peninsula soon became a major source of recruits. Then the Danubian regions were annexed: Raetia (annexed 15BC), Noricum (16BC), Pannonia (9BC) and Moesia (6AD), becoming, with Illyricum, the Principate's most important source of auxiliary recruits for its entire duration. In the East, where the Syrians already provided the bulk of the Roman army's archers, Augustus annexed Galatia (25BC) and Judaea: the former, a region in central Anatolia with a Celtic-speaking people, became an important source of recruits. In N. Africa, Egypt, Cyrene, and Numidia (25BC) were added to the empire. Numidia (E Algeria) was home to the Mauri, the ancestors of today's Berber people. Their light cavalry (equites Maurorum) was highly prized and had alternately fought and assisted the Romans for over two centuries: they now started to be recruited into the regular auxilia. Even more Mauri units were formed after the annexation of Mauretania (W Algeria, Morocco), the rest of the Berber homeland, in 44 AD by emperor Claudius (r.41-54).

Recruitment was thus heavy throughout the Augustan period, with a steady increase in the number of units formed. By 23 AD, there were roughly the same numbers of auxiliaries in service as there were legionaries. This would amount to c.125,000 men (25 legions of 5,000 men), implying c.250 auxiliary regiments. Because of the scarcity of epigraphic evidence from the Julio-Claudian period (compared to the far better-documented auxilia of 100 onwards), we can only identify c.40 of these units.

Illyrian revolt (6-9 AD)

Roman province of Illyricum during the Illyrian revolt (6-9 AD). Area in pink shows Dalmatia, the heartland of the revolt, corresponding largely to modern Bosnia. Areas in pink/yellow represent Roman territory at the time. Red arrows show initial Roman counter-attacks

There had always been an inherent risk in the Julio-Claudian policy of basing ethnically-homogenous auxiliary units in their province of origin: namely that if their own tribe or ethnic group rebelled against Rome (or attacked the Roman frontier from outside the Empire), auxiliary troops could be tempted to make common cause with them. The Romans would then be faced by an enemy that included units fully equipped and trained by themselves, thus losing their usual tactical advantages over tribal foes.

Arminius is the classic example at an individual level: after several years of serving in Rome's forces as prefect of an auxiliary unit, he used the military training and experience he had gained to lead a confederacy of German tribes against Rome, culminating in the destruction of three Roman legions in the Teutoberg Forest in 9 AD, and the abandonment of Augustus' strategy of annexing Germany as far as the Elbe river. (This strategy was never revived by later emperors).

At a collective level, the risk was even greater, as the hugely dangerous Illyrian revolt proved. In 6 AD, several regiments of Dalmatae, a warlike Illyrian tribe, were gathered in one place to prepare to join Augustus' stepson and senior military commander Tiberius in a war against the Germans. Instead they mutinied, and defeated a Roman force sent against them. The Dalmatians were soon joined by the Breuci, another Illyrian tribe that supplied several auxiliary regiments. They gave battle to a second Roman force from Moesia. They lost, but inflicted heavy casualties. The rebels were now joined by a large number of other Illyrian tribes. At risk was the strategic province of Illyricum, recently expanded to include the territory of the Pannonii, an Illyrian tribe based on the west bank of the Danube who were subjugated by Rome in 12-9BC. Illyricum was on Italy's eastern flank, exposing the Roman heartland to the fear of a rebel invasion.

Augustus ordered Tiberius to break off operations in Germany and move his main army to Illyricum. When it became clear that even Tiberius' forces were insufficient, Augustus was obliged to raise a second task force under Tiberius' nephew Germanicus, resorting to the compulsory purchase and emancipation of thousands of slaves to find enough troops, for the first time since the aftermath of the Battle of Cannae two centuries earlier. The Romans had now deployed no less than 15 legions and an equivalent number of auxilia i.e. c150 regiments, including c50 recruited from Roman citizens both free-born and freed slaves (Roman law accorded citizenship to the freed slaves of Roman citizens). In addition they were assisted by a large number of Thracian troops deployed by their king Rhoemetalces, a Roman amicus (ally)Template:Hcref a grand total of c200,000 men.

They faced further reverses on the battlefield and a bitter guerrilla war in the Bosnian mountains. It took them three years of hard fighting to quell the revolt, which was described by the Roman historian Suetonius as the most difficult conflict faced by Rome since the Punic wars two centuries earlier. Tiberius finally quelled the revolt in 9 AD. This was just in time: that same year Arminius destroyed Varus' three legions in Germany. The Roman high command was in no doubt that Arminius would have formed a grand alliance with the Illyrians.

Later Julio-Claudians (14-68 AD)

Significant development of the auxilia appears to have taken place during the rule of the emperor Claudius (41-54 AD).

A minimum term of service of 25 years was established, at the end of which the retiring auxiliary soldier, and all his children, were awarded Roman citizenship. This is deduced from the fact that the first known Roman military diplomas date from the time of Claudius. This was a folding bronze tablet engraved with the details of the soldier's service record, which he could use to prove his citizenship.Template:Hcref Claudius also decreed that prefects of auxiliary regiments must all be of equestrian rank, thus excluding centurions from such commands. The fact that auxiliary commanders were now all of the same social rank as most tribuni militum, (military tribunes, a legion's senior staff officers) Template:Hcref, probably indicates that auxilia now enjoyed greater prestige. Indigenous chiefs continued to command some auxiliary regiments, and were probably granted equestrian rank for the purpose. It is also likely that auxiliary pay was standardised at this time, but we ónly have estimates for the Julio-Claudian period.

Auxiliary uniform, armour, weapons and equipment were probably standardised by the end of the Julio-Claudian period. Auxiliary equipment was broadly similar to that of the legions (see Section 2.1 below for possible differences in armour). By 68 AD, there was little difference between most auxiliary infantry and their legionary counterparts in equipment, training and fighting capability. The main difference was that auxilia contained combat cavalry, both heavy and light, and other specialised units that legions lacked.

Claudius annexed to the empire three regions that became important sources of auxiliary recruits: Britannia (43AD), and the client kingdoms of Mauretania (44) and Thracia (46). The latter became as important as Illyria as a source of auxiliary recruits, especially cavalry and archers. Britain in mid-2nd century contained the largest number of auxiliary regiments in any single province: c60 out of c440 (14%).

By the rule of Nero (54-68), auxiliary numbers may have reached, by one estimate, c200,000 men, implying c400 regiments. The number of regiments probably did not increase greatly for the rest of the Principate- Hassall gives a figure of c440 regiments in mid 2nd century- but their total effectives increased more substantially to c250,000 due to the introduction of double-strength (milliariae) units in the Flavian period.

Revolt of the Batavi (69-70AD)

Rhine frontier of the Roman empire, 70AD, showing the location of the Batavi in the Rhine delta region. Roman territory shaded dark

The second major episode of auxiliary mutiny came over half a century after the Illyrian revolt. The Batavi were a sub-tribe of the Germanic Chatti tribal group who had migrated to the region between the Old Rhine and Waal rivers (still today called the Betuwe after them) in what became the Roman province of Germania Inferior (S Netherlands). Their land, though potentially fertile alluvial deposits, was largely uncultivable, consisting mainly of Rhine delta swamps. Thus the Batavi population it could support was tiny: not more than 35,000 at this time. But they were a warlike people, skilled horsemen, boatmen and swimmers. They were therefore excellent soldier-material. In return for the unusual privilege of exemption from tributum (direct taxes on land and heads that most peregrini were subject to), they supplied a disproportionate number of recruits to the Julio-Claudian auxilia: one ala and 8 cohortes. They also provided most of Augustus' elite personal bodyguard unit (Germani corpore custodes), which continued in service until 68 AD. The Batavi auxilia amounted to c5,000 men, implying that for the entire Julio-Claudian period, over 50% of all Batavi males reaching military age (16 years) may have enlisted in the auxilia. Thus the Batavi, although just c0.05% of the total population of the empire in 23 AD, supplied c4% of the total auxilia i.e. 80 times their proportionate share. They were regarded by the Romans as the very best (fortissimi, validissimi) of their auxiliary, and indeed all, their forces. In Roman service, they had perfected a unique technique for swimming across rivers wearing full armour and weapons.Template:Hcref

Julius Civilis (clearly an adopted Latin name, not his native one) was a hereditary prince of the Batavi and the prefect of a Batavi cohort. A veteran of 25 years' service, he had distinguished himself by service in Britain, where he and the 8 Batavi cohorts had played a crucial role in both the Roman invasion in 43 AD and the subsequent subjugation of southern Britain. By 69, however, Civilis, the Batavi regiments and the Batavi people had become utterly disaffected with Rome. After the Batavi regiments were withdrawn from Britain to Italy in 66, Civilis and his brother (also a prefect) were arrested by the governor of Germania Inferior on false suspicion of treason: his brother was executed, and Civilis sent to Rome in chains for judgement by Nero. (The difference in treatment may indicate that his brother was still a peregrinus, while Civilis, as his name implies, was a Roman citizen which entitled him to have his case heard by the emperor). While Civilis was in prison, Nero was overthrown by the governor of Hispania, Galba, thereby ending the rule of the Julio-Claudians. Galba acquitted Civilis and allowed him to return home. But back in Germania Inferior it seems he was arrested again by the new governor Vitellius, at the urging of the local legions which demanded his execution. Meanwhile, Galba disbanded the imperial bodyguard unit, thus alienating several hundred crack Batavi troops, and indeed the whole Batavi nation who regarded it as a grave insult. At the same time, relations collapsed between the Batavi cohorts and the legion they had been attached to since the invasion of Britain 25 years earlier (XIV Gemina): their mutual hatred erupted in open fighting on at least two occasions.

At this juncture, the Roman empire was convulsed by its first major civil war since the Battle of Actium exactly a century earlier. The cause was the fall of the Julio-Claudian dynasty. The heirs of Augustus, the founder of the professional army, had enjoyed the automatic and fervent loyalty of ordinary legionaries in the frontier armies. But Galba had no such legitimacy in their eyes. Supreme power was now open to whichever general was strong enough to seize it (and keep it). First, Galba's deputy, Otho, carried out a coup against his leader, who was murdered by the Praetorian Guard. Then, in quick succession, two powerful generals, Vitellius and Vespasian, mutinied and led their armies to Rome in a titanic struggle (the Year of the Four Emperors). Otho's army was defeated by Vitellius. Finally Vitellius lost to Vespasian, who succeeded in establishing a new dynasty (the Flavians 69-96).

Civilis was released by Vitellius in early 69, when the latter, having launched his mutiny against Otho, was in urgent need of the Batavi's military support. The Batavi regiments duly helped Vitellius overthrow Otho at the Battle of Bedriacum. The Batavi regiments were then ordered to return home. But at this point came the mutiny of Vespasian, commander of forces in Syria. Vitellius' general in Germania Inferior, ordered to raise more troops, squandered the goodwill of the Batavi by attempting to conscript more Batavi than the maximum stipulated in their treaty. The brutality and corruption of the Roman recruiting centurions (including incidents of sexual assault on Batavi young men) brought already deep discontent in the Batavi homeland to the boil.

Civilis now led his people in open revolt. Initially, he claimed he was supporting his friend from British days Vespasian's bid for power. But the uprising soon became a bid for independence. Civilis took advantage of the fact that some legions were absent from the Rhine area due to the civil war, and the rest under-strength. In addition, the Roman commanders and their rank-and-file soldiers were divided by loyalty to rival emperors. Civilis quickly won the support of the Batavi's neighbours and cousins, the Cananefates, who in turn won over the Frisii. First the rebel allies captured two Roman forts in their territory, and a cohort of Tungri defected to Civilis. Then 2 legions sent against Civilis were defeated when their 3 companion Batavi auxiliary regiments defected to his side. Then a further 8 Batavi regiments joined him. Several other German and Gallic units sent against him deserted, as the revolt spread to the rest of Gallia Belgica, including the Tungri, Lingones and Treviri tribes and even beyond the Rhine. The classis germanica (Rhine flotilla), largely manned by Batavi, was seized by Civilis. By now, Civilis commanded at least 7,000 Roman-trained and equipped auxiliary troops (as well as a much larger number of tribal levies). He was able to destroy the two remaining legions in Germania Inferior (V Alaudae and XV Primigenia). By this stage Rome's entire position on the Rhine and even in Gaul was imperilled. It took a huge task force of 8 legions to finally defeat the Batavi and the Gallic rebels. Tacitus' surviving narrative breaks off as he describes a meeting on an island in the Rhine delta between Civilis and the Roman commander Petillius Cerialis to discuss peace terms. We do not know the outcome of this meeting or Civilis's ultimate fate. But in view of his former friendship with Vespasian, who had already offered him a pardon, and the fact that the Romans still needed the crack Batavi troops, it is likely that the terms were lenient by Roman standards. Since Petilius Cerialis took a number of reconstituted Batavi units with him to Britain, and 5 Batavi units are attested in mid 2nd century, it is clear that Rome's traditional quasi-genocide of rebel tribes (massacres, pillaging and mass deportations into slavery) was not applied in this case. Indeed the Batavi regiments continued to serve with special distinction in Britain and elsewhere for the rest of the 1st centuryand beyond. Even as late as 395, units with the Batavi name were classified as elite praesentales e.g. equites Batavi seniores (cavalry) and auxilia Batavi seniores (infantry).

Flavian era (69-96 AD)

The revolt of the Batavi appears to have led to a radical change in the Roman government's policy on auxiliary deployment. In the Julio-Claudian period, auxiliary regiments were generally stationed in their home areas, except during periods of major crises such as the Cantabrian Wars, when they were deployed temporarily in theatre. But the Batavi revolt proved that in times of civil strife, when legions were far from their bases campaigning for rival claimants to the imperial throne, it was dangerous to leave provinces in the hands of auxiliary regiments recruited from the indigenous nation. In the Flavian period (69-96) it appears to have become standard policy for auxiliary units to be permanently based in provinces other than their home province. Furthermore, native nobles were no longer permitted to command auxiliary units from their own nation. The new policy was apparently successful. We know of no other major incident of auxiliary mutiny after the Batavi revolt (although surviving literary sources for the late 1st, 2nd and 3rd centuries are so poor that we cannot be certain).

The new policy began with the transfer to Britain in 70 AD of 5 reconstituted Batavi regiments (1 ala and 4 cohortes)under Petillius Cerialis, who had suppressed the Civilis revolt and then embarked on the governorship of the island. The great majority of regiments probably founded in the first century were stationed away from their province of origin in the second e.g. of 13 British regiments recorded in mid 2nd century, none are stationed in Britain.Template:Hcref Of the c60 auxiliary units identified in Britain in the early 2nd century, none carries a British name.

The long-term posting of a regiment to an alien province resulted in a steady dilution of its ethnic integrity, as most new recruits were probably recruited from the new host population. L. Keppie argues in Cambridge Ancient History that eventually, after being based in a province for several decades, the regiment would acquire a new ethnic identity, that of the host province. The unit's name would thus become a mere curiosity devoid of meaning, although some of its members might inherit foreign names from their veteran ancestors. This view has to be qualified, however, as evidence from military diplomas and other inscriptions shows that some units continued to recruit in their original home areas (e.g. Batavi units stationed in Britain); and that the Danubian provinces remained key recruiting grounds for units stationed all over the empire.

The Flavian period also saw the first formation of large, double-size units, both infantry and cavalry, of a nominal strength of 1000 men (cohors/ala milliaria) These were the mirror image of the double-strength first cohorts of legions also introduced at this time. Such units remained a minority of the auxilia: in mid-2nd century, they constituted 13% of units, containing 20% of total manpower.

Later Principate (97-284)

Roman cavalry spatha, a longer (median blade length: 780mm) sword, designed to give the rider a longer reach than the gladius

In 106 AD, emperor Trajan finally defeated the Dacian kingdom of Decebalus and annexed it as the Roman province of Dacia Traiana. By mid 2nd century, there were 47 auxiliary regiments stationed there, about 10% of the total auxilia. In Britain there were c60. Since by the late 2nd century, most recruits to these units were probably local provincials, Britons and Dacians alone probably provided c25% of all auxilia recruits by that time (recruits to those units who were not Britons/Dacians are compensated by the latter in British/Dacian units in other provinces).

At the midway point in this period, there were probably c440 auxiliary regiments. At this time, the auxilia probably numbered a total of c250,000 effectives i.e. roughly twice the strength in 23 AD. Of the total, c150,000 were infantry, c75,000 cavalry and c25,000 archers (mounted and foot). This compares with 154,000 legionaries (28 legions of 5,500 men each) at this time, of which just 3,360 were cavalry. (See section 3: Auxilia deployment in the 2nd century, below).

During the second century some units with the new names numerus ("group") and vexillatio ("detachment") appear in the diploma record. Their size is uncertain, but was likely smaller than the regular alae and cohortes. Some older scholars see these names as specifically denoting the irregular symmachiarii, ethnic units outside the regular auxilia (see section 2.4 Irregular units, below). But the present consensus is that they were part of the regular auxiliary organisation These unit names were to become prominent in the 4th century.

In 212, the constitutio Antoniniana (Antonine decree) of Emperor Caracalla granted Roman citizenship to all the free inhabitants of the Empire- the peregrini - thus abolishing their second-class status. But this does not necessarily mean that the distinction between the all-citizen legions and the auxiliaries was also abolished. It simply gave the legions a much wider recruitment base. Legions continued to be limited to Roman citizens, but were now able to recruit any male free resident of the empire. Auxiliary units were now probably majority Roman citizens: but they probably continued to recruit non-citizen barbari from outside the Empire's borders in large numbers, as they had done since the time of Augustus (see Some Unresolved Issues, below).

In the 3rd century, a small number of regular auxiliary units units appear in the record that, for the first time, bear the names of barbarian tribes from outside the empire e.g. the ala I Sarmatarum attested in 3rd-century Britain. This was probably an offshoot of the 5,500 surrendered Sarmatian horsemen posted on Hadrian's Wall by emperor Marcus Aurelius in c175. This unit may be an early example of a process whereby irregular units of barbari (symmachiarii or foederati) were transformed into regular auxilia. This process intensified in the 4th century: the Notitia Dignitatum, a key document on the late Roman army, lists a large number of regular units with barbarian names.

Fourth century

In the fourth century, the Roman army underwent a radical restructuring which is little understood due to the scarce and ambiguous evidence. In the rule of Diocletian (284-305), the traditional Principate formations of legiones, alae and cohortes appear to have been broken up into smaller units, many of which bore a variety of new names. Under Constantine I (r.312-337) it appears that military units were classified into three grades based on strategic role and to some extent quality: praesentales, elite units normally based near the late imperial capitals of Mediolanum (Milan) and Byzantium (Constantinople) and available to emperors as escort forces; comitatenses, higher-grade interception forces based in dioceses (major provincial divisions) well behind their frontiers; and limitanei, lower-grade border troops. (See Late Roman army).

The old Principate auxilia regiments provided the basis for units at all three grades. The Notitia Dignitatum lists c70 alae and cohortes that retained 2nd century names, mostly limitanei. But traces of other auxilia regiments can be found in the praesentales and comitatenses armies.

The late 4th century writer on military affairs Vegetius complains of contemporary young men joining the "auxilia" in preference to the "legions" to avoid the latter's tougher training and duties.But it is unclear what types of units he was referring to. It is possible that those older terms were still popularly used (misleadingly) to mean limitanei and comitatenses respectively. In any event, his quote in no way describes accurately the Principate auxilia, many of which were the best units in the army of the Principate.

Relationship with legions

File:Roman cavalry lg.jpg

Auxiliary cavalryman (eques alaris or alarius) with spatha (sword), showing the long grip which allowed it to be wielded double-handed. In addition, he carries a hasta (spear), and oval shield (not visible, over his left shoulder). Note the reconstructed four-horned sella (Roman saddle). This was designed to give a firm seat, to compensate for the absence of stirrups, which were not introduced until the 6th century

During the Principate, recruitment into the legions was restricted to Roman citizens only. This rule, which derived from the pre-Social War Republican army, was strictly enforced. The few documented exceptions made, such as during emergencies and for the illegitimate sons of legionaries, do not imply that the rule was routinely ignored.Template:Hcref But did the auxilia differ in other respects from their legionary counterparts?

The role of the early Empire auxilia corps vis-a-vis the legions has often been misunderstood. This is ultimately due to the influence of Vegetius, an ancient writer on Roman military doctrine and practices. Vegetius' work De re militari contains much useful information, but it is misleading overall. This is because Vegetius fails to fit his descriptions of army practices into a chronological framework. By his own account, Vegetius' sources stretch 3 centuries from Cato the Elder in c200BC to the emperor Hadrian, while he himself wrote 2 centuries after the latter, when the army was radically different. His work thus contains a jumble of concepts from different eras, largely out of context. Thus what he writes about "auxilia" could relate to any of the various types of auxiliary forces in 500 tyears of the Roman army's history: the Latin socii, the contingents provided by client kings in the late Republic/Principate, the professional Augustan auxilia or indeed the limitanei border troops of his own day. Furthermore, not having military experience himself, his understanding of the practical value of the doctrines he espoused was minimal.

Misconceptions ultimately inspired by Vegetius include the following:

(i) auxilia were inferior to the legions in training and combat capability
(ii) auxilia contained only "light" infantry whilst legions were heavy infantry
(iii) auxilia infantry did not fight in the main battle-line, which was the preserve of the legions
(iv) auxilia only functioned as support troops, assisting legionary operations, but never campaigning independently
(v) auxilia were border troops, manning border and beyond-border forts, while legions were based well behind the border as a strategic reserve, only intervening if there was a major incursion

These propositions may have been true, to some extent, in the Republican period. But there is strong evidence that they were largely false by the end of the Julio-Claudian period.

(i) Quality

Vegetius' comment about young men preferring to join the auxilia in order to escape the harsher discipline and training of the legions is the origin of the view that legionaries were higher quality troops than auxiliaries. The main evidence used to support this view is that legionaries were paid a higher salary. There is no clearcut evidence about the differentials between legionary and auxiliary pay. Outdated scholars held that auxiliary pay was as little as one-third of the legionary level. But more recent studies have concluded that the differential was much smaller (just 20% less) and in any case only applied to infantry. Equites cohortales (cohort cavalry) were paid the same as legionaries, and equites alares (ala cavalry) c20% more. The legionary's higher pay is probably due more to his social superiority as a Roman citizen than to any higher military proficiency. Tacitus' account of the clashes between Batavi auxiliaries and Roman legionaries during the Batavian revolt shows that there was no appreciable difference in quality between them. Indeed, in terms of cavalry, it was the alares who were the elite. The tiny cavalry arms of legions (just 120 men out of 5500) were suitable only for reconnaissance and communications duties, rather than combat.

(ii) Armour

The view that auxilia were light troops originates from Vegetius' comment that "auxilia are always joined as light troops with the legions in the line". It is true that some specialist units in the auxilia, such as Syrian archers and Numidian cavalry wore light armour (or none). But they were a small minority of the auxilia. Most auxiliary cohortes contained heavy infantry similar to legionaries. Much has been made of the clear difference in armour between the two corps shown on Trajan's Column. This is a monument erected in 113 in Rome to commemorate the conquest of Dacia by Emperor Trajan (ruled 97-117): its bas-reliefs are a key source for Roman military equipment. Auxilia are generally shown wearing chain mail (lorica hamata) cuirasses or simple leather corslets, and carrying oval shields. Legionaries are depicted wearing laminated-strip armour (lorica segmentata) and with curved rectangular shields. But on another Trajanic monument, the Adamclisi Tropaeum, the lorica segmentata does not appear at all, and legionaries and auxilia alike are depicted wearing either chain mail or scales (lorica squamata). There is general recognition that the Adamclisi monument is a more accurate portrayal of normality, with the segmentata used rarely, maybe only for set-piece battles and parades. The figures in Trajan's Column are highly stereotyped, in order to distinguish clearly between different types of troops.Template:Hcref In any event, both corps were equipped with the same weapons: gladius (a close-combat stabbing sword) and javelins, although the type of javelin known as a pilum seems to have been provided to legionaries only. Goldsworthy points out that the equipment of both corps were roughly equal in weight. If there was a difference in armour, it was probably due, again, to non-military reasons: by providing legionaries with more protective (and expensive) glamorous armour, the army was highlighting their social superiority, just as it did with higher pay. During the 3rd century, when all peregrini were granted citizenship, and therefore legionaries lost their social superiority, the lorica segmentata and the rectangular shield disappeared.

(iii) Combat role

Auxiliary cohortes (except specialised units) were heavy infantry that fought in the line like the legions. There is no evidence that cohortes fought in a looser order than the legions. It appears that in a set-piece battle-line, auxiliary infantry would normally be stationed on the flanks, with legionary infantry holding the centre e.g. as in the Battle of Watling Street (60 AD), the final defeat of the rebel Britons under queen Boudicca. This was a tradition inherited from the Republic, when the precursors of auxiliary cohortes, the Latin alae, occupied the same position in the line. But the flanks of the line required equal skill to hold as the centre.

(iv) Operational autonomy

An auxiliary regiment would normally be attached to a legion for operational purposes, with the praefectus under the command of the legatus legionis (the legion's commander). The period that it was so attached could be a long one e.g. the 8 Batavi cohortes apparently attached to legion XIV Gemina for the 26 years from the invasion of Britain in 43 AD to the Civil War of 69. But a legion had no standard, permanent complement of auxilia: its attached auxiliary units were changed and varied in number according to operational requirements at the behest of the legatus Augusti (provincial governor), and of the high command in Rome.

But the fact that auxiliary regiments were attached to a legion does not mean that they were not capable of, or were not permitted to, carry out operations unaccompanied. Indeed, in view of their lack of combat cavalry, it was the legions which could not campaign independently. Examples of major operations carried out by auxilia alone is the campaign against the Iceni tribe in Britain under governor Ostorius Scapula in 47, and the rescue of Brigantian queen Cartimandua in 52. On Trajan's Column, some 20 major battle scenes are shown. Auxilia take part in 19 of these, in 12 of which they are fighting alone, unaccompanied by legionaries.

(v) Strategic role

It is true that in some provinces, e.g. Britain, legionary bases were well behind the frontline. In Britain, the legionary fortresses of Chester and York were over 100 km from Hadrian's Wall. But in other provinces, legions were stationed right on the border: e.g. Regensburg, Vienna and Budapest on the Danube. In Britain, it is true that the main responsibility for garrisoning the forts on the Wall and beyond lay with the auxilia. But there is growing evidence that such forts were also garrisoned by legionary detachments, and even by mixed legionary/auxiliary garrisons

In conclusion, there were no significant differences in training, equipment, fighting capability or tactical role between legionary infantry and their auxiliary counterparts. In cavalry, auxiliaries were superior, as they were combat-capable, whereas legionary cavalry was not. In archery, legions had no capability at all.

The question arises as to why the citizens-only rule was retained for such a long period, especially as it must have caused significant recruitment problems in those provinces with a small pool of citizens e.g. Britain, where Mattingly doubts that the c50,000 Roman citizen body could have supplied all the c600 recruits required annually by the 3 legions based in the province. The answer must lie in concern for national security. The experience of the Batavi revolt probably convinced Rome's rulers that it was essential to maintain a significant section of the army whose national loyalty could be relied upon in all circumstances.

Unit types and structure

Standard units

The following table sets out the official, or establishment, strength of auxiliary units in the 2nd century. The real strength of a unit would fluctuate continually, but would likely have been somewhat less than the establishment most of the time.

ROMAN AUXILIARY REGIMENTS: TYPE, STRUCTURE AND STRENGTH.

Unit type	Service	Unit commander	Sub-unit commander	No of sub-units	Sub-unit strength	Unit strength
Ala quingenaria	cavalry	praefectus	decurio	16 turmae	30	480
Ala milliaria	cavalry	praefectus	decurio	24 turmae	30	720
Cohors quingenaria	infantry	praefectus*	centurio	6 centuriae	80	480
Cohors milliaria	infantry	tribunus militum**	centurio	10 centuriae	80	800
Cohors equitata quingenaria	mixed infantry/ cavalry	praefectus	centurio (inf) decurio (cav)	6 centuriae 4 turmae	80 30.	600 (480 inf/120 cav)
Cohors equitata milliaria	mixed infantry/ cavalry	tribunus militum**	centurio (inf) decurio (cav)	10 centuriae 8 turmae	80 30	1,040 (800 inf/240 cav)

Sources: M. Hassall in Cambridge Ancient History Vol XI 332-4
* tribunus militum in original c.R. cohortes
** praefectus in Batavi and Tungri cohortes milliariae

NOTE: There is dispute about some of the figures above, which are the modern mainstream view. Some scholars hold that an ala was 512 strong (from Arrian Ars Tactica 17.3). This would make an turma 32, rather than 30, strong. Also it has been suggested that a centuria in a cohors equitata was 60 rather than 80-strong: this would make the total strength of the unit 480, the same as a purely infantry cohors, rather than 600.

Auxiliary ranks

As stated above, by the end of Claudius' rule (54 AD), all commanders of auxiliary regiments, known as praefecti or tribuni militum, were Roman citizens of equestrian rank. Unlike a legatus legionis (who had an officer staff of 6 tribuni militum and 1 praefectus castrorum), an auxiliary praefectus does not appear to have enjoyed the support of purely staff officers. The possible exception is an attested beneficiarius ("deputy"), who may have been the praefectus' second-in-command, if this title was a regular rank and not simply an ad hoc appointment for a specific task. Also attached to the praefectus were the regiment's signifer (standard-bearer) and cornucen (horn-blower).

Compared to legionary centurions, little is known about auxiliary centuriones and decuriones. The existing evidence is that such officers could be directly commissioned as well as promoted from the ranks. The latter could be promotions from the legions as well as from the unit's own ranks. In the Julio-Claudian period auxiliary centuriones and decuriones were a roughly equal split between citizens and peregrini, though later citizens became predominant due to the spread of citizenship among military families.

Below centurion rank, a cohort's centuriae appear to have the same ranks as legionary centuriae i.e. the group of junior officers known as principales: optio (the centurion's deputy), signifer (standard-bearer) and tesserarius (officer of the watch), in order of rank. In the turmae of cohortes equitatae (and of alae?), the decurion's second-in-command was probably known as a curator, responsible for horses and caparison. Otherwise the other ranks were probably the same as for the centuriae. As in the legions, the principales, together with some regimental specialists, were classified in two general ranks: duplicarii ("double-pay men") and sesquiplicarii ("one-and-a-half-pay men"). These ranks probably compare most closely with the modern junior ranks of sergeant and corporal.

At the bottom end of the rank pyramid, ordinary soldiers held the official ranks of pedes (foot soldier in a cohors), eques (cavalryman in a cohors equitata) and gregalis (ala cavalryman).

Besides combat effectives, regiments also contained specialists, some of whom held the ranks of duplicarius or sesquiplicarius, others were common soldiers with the status of milites immunes ("exempt soldiers" i.e. exempt from normal duties). Ranking specialists included the medicus (regimental doctor), veterinarius (veterinary doctor, in charge of the care of horses, pack animals and livestock), custos armorum (keeper of the armoury), cornicularius (clerk in charge of all the regiment's records and paperwork).

Pay

There is no certain evidence about the levels of auxiliary pay, even less than the already meagre evidence for legionary pay. But there is a consensus about two features: (1) pay differentials between ranks were very high compared to modern armies; (2) that not all types of auxilia were paid at the same rate.

The pay of a praefectus of an auxiliary regiment in the early 2nd century has been estimated at over 50 times that of a miles (common soldier). (This compares to a full colonel in the British Army, who is currently paid c5 times a private's salary). We do not know pay rates for centuriones and decuriones, but these are also believed to have amounted to many times that of a miles. Among the lowest ranks, on the other hand, the gaps were more modest, and comparable with today's: a duplicarius earned twice as much as a simple miles, similar to the differential between a sergeant and a private in today's army. The reason for the huge gap between the top and the bottom of the pyramid is that Roman society was far more class-ridden than a modern one. A praefectus was not just a senior officer. He was also a Roman citizen (which most of his men were not) and, as a member of the equestrian order, an aristocrat. The social gulf between him and a peregrinus soldier was immense, and the pay reflected that fact. However, during the 3rd century, the pay differentials seem to have been greatly eroded by runaway inflation.

There also existed a hierarchy of pay between types of auxiliary, with cavalry higher paid than infantry. One recent estimate is that in the time of Augustus, the annual pay structure was: eques alaris (gregalis) 263 denarii, eques cohortalis 225, and cohors infantryman 188. The same differentials (of c20% between grades) seem to have existed at the time of Domitian (r81-96). However, Goldsworthy points out that the common assumption that rates of pay were universal across provinces and units is unproven. It is possible, for example, that pay may have been higher for certain elite units such as alae singularium or cohortes Batavorum or specialist units such as sagittarii.

Equites cohortales

The traditional view of scholars, as expounded by G.L. Cheesman, was that the cavalry contingent of a cohors equitata were just a mounted infantry with poor-quality horses. They would use their mounts simply to reach the combat zone and then would dismount to fight. This view is today discredited. Although it is clear that equites cohortales did not match equites alares in quality (hence their lower pay), the evidence is that they fought as cavalry in the same way as the alares and often alongside them. Their armour and weapons were the same as for the alares.

Specialised units

In the Republican period, the standard trio of specialised auxilia were Balearic slingers, Cretan archers and Numidian light cavalry. These functions continued in the 2nd century auxilia, plus a few new ones:

Sagittarii

Archers, from sagitta = "arrow": Archer units recorded in the 2nd century: 8 alae sagittariorum (mounted archers), 18 cohortes sagittariorum (foot archers) and 6 cohortes sagittariorum equitatae (mixed foot/mounted archers). These 32 units (of which 4 were milliary) would have comprised officially 17,600 archers. (But there were probably more: see section 3 below). They were now predominantly of Syrian origin, just one unit, cohors I Cretum sagitt. eq., bearing the name of the Cretan archers who had traditionally served the Republic.Template:Hcref

Three distinct types of archers are shown on Trajan's Column: (a) with scalar cuirass, conical helmet and cloak; (b) without armour, cloth conical cap, and long vest; (c) equipped in the same way as general auxiliary foot soldiers. The first two types were probably Syrian units; the third type probably Thracian.

It is unclear from the evidence if all sagittarii units contained only archers (see Unresolved Issues (7), below).

Equites Maurorum

Light cavalry, from equites = "horsemen": Light cavalry still came from Mauretania (Mauretania and Numidia were merged as provinces; their inhabitants were the same people, the Mauri (from which derives the English term "Moors". They were the ancestors of the Berber people of modern Algeria and Morocco). On Trajan's Column, Mauri horsemen are shown riding bare-back with a simple halter to control their mounts. They wear no armour, just a short tunic. Their weaponry cannot be discerned due to stone erosion, but probably consisted of short spears. The riders are depicted with long hair in dreadlocks. It is unclear what proportion of the Moorish cavalry were regular auxilia units as opposed to irregular barbari allied units.

Funditores

Slingers, from funda = "sling": No slinger units appear in the diploma record. However, slingers are portrayed on Trajan's Column. They are shown unarmoured, wearing a short tunic. They carry a cloth bag, slung in front, to hold their shot (glandes). It seems likely that at least one cohort of slingers took part in the Dacian campaigns.

Contarii

Lancers, from contus = a heavy long lance): From the second century appear units of special heavy cavalry, covered from head to toe in scalar armour. Their numbers were probably considerably expanded in the 3rd century. Based on Sarmatian and Parthian models, they were called contarii, cataphractarii and clibanarii. Together with new units of light mounted archers, they were designed to counter Parthian (and, in Pannonia, Sarmatian) battle tactics. Parthian armies consisted largely of cavalry. Their standard tactic was to use light mounted archers to weaken and break up the Roman infantry line, and then to rout them with a charge by the cataphractarii. The only special heavy cavalry units to appear in the 2nd century record are: ala I Ulpia contariorum and ala I Gallorum et Pannoniorum cataphractaria stationed in Pannonia and Moesia Inferior respectively in the 2nd century. But there must have been several more such regiments in the East.

Singulares

Imperial escort cavalry units, from singuli = "attached to one individual": Since the days of Augustus (who had German bodyguards: Germani corpore custodes), emperors had used non-Romans as their personal guards, presumably so that their loyalty could not be suborned by rival claimants for imperial power. However, the German bodyguard unit was abolished by emperor Galba in 69 AD. They were replaced by the equites singulares Augusti, (literally = "personal cavalry of the emperor" i.e. imperial horseguards) a unit made up of the best cavalry the auxilia could offer: their core component were the Batavi, as it had been for the bodyguard unit. This was the only unit of the Praetorian Guard which recruited non-citizens. Starting as a milliary ala (720-strong), it grew steadily in size, reaching 2000 men at end 2nd century. They would always accompany the emperor on tours of the provinces and campaigns. In addition to the ala at Rome, it appears that after some campaigns, detachments of singulares were permanently left behind in the provinces, becoming regular alae, but retaining the prestigious singulares title and crack reputation e.g. Ala I Flavia singularium stationed in Raetia in mid 2nd century. On Trajan's Column, singulares are easily identifiable because they always accompany the Emperor himself, and are not dressed for battle: they do not wear a cuirass, but marching clothes (tunics and cloaks). Their standards carry the same lightning-and-thunderbolt motif (with or without wings) as the legions.

Dromedarii

Camel-mounted units: Just one of these is attested from the 2nd century, ala I Ulpia dromedariorum milliaria in Syria, but there must have been more to patrol the deserts of Arabia and North Africa.

Exploratores

Reconnaissance units, from explorare = to scout): Examples include two numeri exploratorum attested in the 3rd century in Britain: Habitanco and Bremenio (both names of forts). Little is known about such units.

Irregular units

Throughout the Principate period, there is evidence of ethnic units of barbari outside the normal auxilia organisation fighting alongside Roman troops. To an extent, these units were simply a continuation of the old client-king levies of the late Republic: ad hoc bodies of troops supplied by Rome's puppet kinglets on the imperial borders for particular campaigns. But some clearly remained in Roman service beyond the campaigns, keeping their own native leadership, attire and equipment and structure. These units were known to the Romans as symmachiarii (derived from Greek = "co-fighters") or foederati (treaty troops from foedus, "treaty") Due to scarce evidence, we do not know how many such units existed or for how long.

The symmachiarii make their first official appearance on Trajan's Column. Here they are portrayed in a standardised manner: with long hair and beards, barefoot, stripped to the waist, wearing long trousers held up by wide belts and wielding clubs. In reality several different tribes supported the Romans in the Dacian wars. Their attire and weapons would have varied widely. The Column stereotypes them with the appearance of a single tribe, probably the most outlandish-looking, to differentiate them clearly from the regular auxilia. Judging by the frequency of their appearance in the Column's battle scenes, the symmachiarii were important contributors to the Roman operations in Dacia. Another example of symmachiarii are the 5,500 Sarmatian cavalrymen sent by Emperor Marcus Aurelius (ruled 161-180) to garrison a fort on Hadrian's Wall after their defeat in the Marcomannic Wars

Everyday life of auxiliaries

The professional soldiers of the Principate, both legionary and auxiliary, were in combat operations for only a tiny fraction of their working careers. Most of their days were spent on routine duties, both military and non-military. These, together with soldiers' social and private lives, are virtually ignored by the contemporary historians such as Tacitus and Dio Cassius. But modern archaeology, especially excavation of Roman forts, is casting an enormous amount of light on this topic.

Until the breakthrough discovery in the 1970's of the Vindolanda Tablets, most of the evidence for everyday life of auxiliaries was found in papyri, recovered mostly in Egypt. However, the papyrus evidence for auxilia, as opposed to legions, is relatively thin and inevitably relating mostly to units in Egypt and the East.

The Vindolanda Tablets concern only auxiliary units and emanate from the northwestern provinces of the empire, thus filling some gaps in the papyri evidence. They consist of a series of letters and memoranda, engraved on wooden tablets, between officers of three auxiliary regiments from Germania Inferior that succeeded each other in the fort of Vindolanda in northern England. They date from the period 85-122, preceding the construction of Hadrian's Wall. Template:Hcref

The scarcity of evidence today is due to organic decomposition, not a lack of written documentation in the Roman army. On the contrary, the surviving corpus shows that the army was highly bureaucratised. Even minor matters such as soldiers' requests to their praefectus for leave (commeatus) had to be submitted in writing. Records were kept on all individual soldiers and there is evidence of filing systems. From what has been discovered at Vindolanda, it can be deduced that the garrison in Britain alone generated tens of millions of documents. Only an infinitesimal fraction survives today.

The most informative documents are renuntiae, unit strength and deployment reports which were drawn up periodically for the regiment's praefectus; and pridiana, or duty rosters, (from pridie "the previous day"), which were prepared daily for the following day and presumably posted on notice-boards in the fort for all to see. These collectively show that auxiliary soldiers were engaged in a wide variety of activities, on-base and off-base, military and non-military in nature.

Military duties

The routine military duties of auxiliaries included patrolling, guard duty, and weapons training. These were not limited to the regiment's base fort and its vicinity only: the Vindolanda tablets show that detachments of the unit could be deployed in several different locations at once: one renuntia shows a detachment of nearly half the effectives of cohors I Tungrorum deployed at another fort. A papyrus renuntia for cohors I Hispanorum veterana equitata in Moesia Inferior (105 AD) reports a cavalry turma on a scouting mission (exploratum) across the Danube. Combat training and exercises were a central part of an auxiliary's weekly routine. One tablet probably contains a scathing comment of an officer about the horsemanship of young provincial trainees in the cohors equitata: "on horseback, too many of the pathetic little Brits (Brittunculi) cannot swing their swords properly or throw their javelins without losing their balance". Parades were another important part of a regiment's routine. As in today's armies, each day would begin with a roll-call parade (probably called a numeratio). Occasional parades included religious parades in honour of certain gods, especially Jupiter (the supreme god of the Roman pantheon) and Mars, (the god of war), likely accompanied by animal sacrifices and feasting; parades on imperial birthdays, when the portraits (imagines) of the ruling emperor, and of deified previous emperors, would be saluted; and purely military parades such as the rosaliae signorum (decoration of the standards) and demissio, when veterans were discharged after completing their term of service and awarded their diplomas of Roman citizenship. There would also be military exercises, in which soldiers displayed their combat skills, when the regiment was inspected by a high official: the legatus legionis, legatus Augusti or even the emperor himself.

Other fort duties

Non-military duties on-site included the routine chores of fort life (cleaning, washing clothes and equipment, feeding horses) and working in the fort's fabrica (workshop where armour and weapons were made and repaired). An essential activity was the procurement of the supplies the regiment needed. For raw materials, the army purchased what it could locally, and imported the rest from elsewhere. The men of I Hispanorum veterana went as far afield (from Moesia Inferior) as Gaul to procure clothing and grain. For manufactured goods, the regiments would produce some of their needs themselves e.g. evidence of leather tanning and beer brewing at Vindolanda and nearby Catterick fort. The tablets attest the procurement of cereals, beer, animal fodder; manufactured goods such as clothing, nails and vehicle parts; raw materials such as stone, iron, lead, timber, animal hides. Some soldiers with special skills were given the status of immunes, meaning they were exempt from normal duties and chores so they could practice their specialism. Attested specialists include scutarii ("shield-men"), probably blacksmiths and other craftsmen who worked in the fabrica; carpentarii (wagon-drivers, or alternatively carpenters); seplasiarii ("ointment-men"), medical orderlies who worked in the hospitium (fort hospital); balniator (bath attendant); and cervesarius (beer brewer). It is uncertain, however, whether these jobs were all held by milites immunes or some by civilians working for the unit on contract.

Construction

A major non-military activity of the Roman army was construction: the army was a large workforce of fit, disciplined men skilled in building techniques and other crafts: they were on regular salaries anyway, so it was cheaper for the government to use them for big projects, if the security situation in the province allowed, than to hire private contractors. Soldiers naturally built forts and fortifications: Hadrian's Wall itself was built by the army. But they also built much of a province's infrastructure: trunk Roman roads, bridges, docks, canals, aqueducts, entire new cities such as coloniae for veteran legionaries, public buildings (e.g. basilicas and amphitheatres). The army also carried out large-scale projects to increase the land available for agriculture, such as forest clearance, draining marshes (e.g. the large-scale drainage of the Fens in eastern England, which were probably developed as a huge imperial estate) or excavating irrigation channels. Most of the available evidence relates to legionary construction. Template:Hcref But the Vindolanda tablets attest auxiliaries' construction activity: one tablet refers to 12 soldiers detailed to work on the construction of a bath-house (balneum) at Vindolanda. Another possibly refers to the construction of a bridge elsewhere. The Roman military also operated many of the mines and quarries that produced the raw materials they needed for weapons and armour manufacture and for construction. Soldiers would supervise the slave-gangs that generally acted as miners, or mine themselves at times of urgent demand. The renuntia of I Hispanorum veterana records some men at the mines in neighbouring Dardania.

Police duties

Off-site duties included many routine police and even administrative tasks. Provincial governors had only a minimal administrative staff at their disposal, and no regular police force. They therefore relied on their troops for many such duties: escorting the governor or other senior officials, patrolling highways, assisting and escorting tax collectors, carrying official despatches, arresting wanted men. Thus a renuntia shows a detachment of 46 men of I Tungrorum on escort duty (singulares) with the provincial governor's staff.

Highways were routinely garrisoned and patrolled along their entire length. Small detachments of troops would be on duty at the way-stations: mutationes (relay stations where horses could be changed) and mansiones (large wayside inns, with accommodation, stables, taverna and baths). These stations may well be the 6 unidentified locations where small detachments of c10 men, each under a centurion, were deployed according to a renuntia of cohors I Tungrorum. They would check the identities and cargoes of road users and keep the highways clear of robbers: 1 eques of I Hispanorum veterana was reported killed by robbers in a renuntia. They would also assist agents of the procurator (the senior financial official in the province) to collect the portorium, an imperial toll on the carriage of goods on public roads, payable whenever the goods crossed a toll line. Despatch riders (dispositi), normally equites cohortales, would also be stationed at mutationes to form relays to carry messages rapidly between forts. Relays of fresh riders and horses, careering at full gallop, could maintain an average speed of 20 mph (32 km/h): thus an urgent despatch from legionary headquarters at Eboracum (York) to the provincial governor in London (200 miles, 320 km), a journey of two weeks for a single rider and mount, could be delivered in just 10 hours.

Social life

All the Vindolanda documents are written by officers, supporting the view that many of the lower ranks may have been illiterate. The language used is always Latin, usually of a reasonable standard. Most of the authors were Gauls, Britons or Germans, whose native languages were Celtic or Germanic, yet they wrote even to their relatives in Latin. This does not mean that they could no longer speak their native tongues, simply that those tongues never developed a written form. The tablets show that superior officers were addressed as domine ("master") and soldiers of the same rank as frater ("brother") or collega ("comrade"). The letters show that an auxiliary soldier maintained friendships not just in his own regiment, but also in other regiments and even in the legions.

Auxilia deployment in the 2nd century

ROMAN AUXILIARY REGIMENTS: Summary of known deployments c130 AD

Province	Approx. modern equivalent	Alae (no. milliariae)	Cohortes (no. mill.)	Total units	XXX	Cavalry strength*	Infantry strength	Total auxilia	XXX	No legions	Legionaries (infantry)	XXX	TOTAL GARRISON
Britannia	England/Wales	14 (1)	46 (7)	60		11,400	24,320	35,720		3	16,500		52,220
Rhine Frontier
Germania Inferior	S Neth/NW Rhineland	7	19 (2)	26		5,280	9,760	15,040		2	11,000		26,040
Germania Superior	Pfalz/Alsace	2	22 (1)	24		2,700	10,880	13,580		2	11,000		24,580
Danube Frontier
Raetia/Noricum	S Ger/Switz/Austria	5 (1)	17 (4)	22		4,440	9,440	13,880		1	5,500		19,380
Pannonia (Inf + Sup)	E Hungary/Slovenia	12 (2)	22 (6)	34		8,520	12,480	21,000		3	16,500		37,500
Moesia Superior	Serbia	2	7	9		1,560	3,360	4,920		2	11,000		15,920
Moesia Inferior	N Bulgaria/coastal Rom	6	14 (2)	20		4,080	7,360	11,440		1	5,500		16,940
Dacia (Inf/Sup/Poroliss)	Romania	12 (2)	35 (5)	47		9,240	18,400	27,640		2	11,000		38,640
Eastern Frontier
Cappadocia	Central/East Turkey	5	13 (5)	18		3,840	7,840	11,680		3	16,500		28,180
Syria (inc Judaea/Arabia)	Syria/Leb/Palest/Jordan	10 (1)	41 (4)	51		8,640	20,960	29,600		5	27,500		57,100
North Africa
Aegyptus	Egypt	6	11	17		3,840	5,280	9,120		2	11,000		20,120
Mauretania (inc Africa)	Tunisia/Algeria/Morocco	13 (1)	29 (3)	42		8,880	14,880	23,760		1	5,500		29,260
Internal provinces		1	19 (2)	20		2,160	9,760	11,920		1	5,500		17,420
TOTAL EMPIRE		95 (8)	295 (41)	390		74,580	154,720	229,300		28	154,000		383,300

* Cavalry numbers assume that 70% of cohortes are equitatae i.e. contained a cavalry contingent

File:RomanEmpire 125.svg

The Roman empire at the time of emperor Hadrian c125 AD

Overview

The totals above of 390 regiments (95 alae and 295 cohortes) are close to figures in Cambridge Ancient History Vol. XI of 388 regiments (90 alae and 298 cohortes). The slight discrepancies may be due to time parameters used or to new diploma discoveries since CAH XI was published.

The above figures yield a total auxilia establishment in mid 2nd century of 230,000 (75,000 cavalry and 155,000 infantry), compared to 154,000 legionary infantry. This compares with Holder's total figures of 218,000 (75,000 cavalry and 143,000 infantry). Holder's somewhat lower total figure is due to his use of a more restrictive focus period: the rule of Hadrian alone (117-38).

The table shows that legions did not have a standard complement of auxiliary regiments and that there was no fixed ratio of auxiliary regiments to legions in each province. The ratio varied from 11 regiments per legion in Germania Superior to 23 per legion in Dacia.

Missing units

The early 2nd century provides the best evidence for auxilia deployment, due to the large number of diplomas recovered (over 5 diplomas for each year in the period 117-160 have been published). The question arises: how complete a picture of 2nd century deployment do we have? Hassall suggests that there were c440 auxiliary regiments at this time, some 50 more than attested. This is very likely, for the following reasons:

(1) There are a substantial number of regiments which are attested outside the focus period, (i.e . in the late 1st or late 2nd centuries), which probably existed in the early 2nd: we simply have not yet discovered the evidence.

(2) The deployment figures for a couple of provinces, Cappadocia and Moesia Superior, seem implausibly low. Cappadocia in particular was a key strategic province. To the southeast, the river Euphrates formed a direct frontier with the Parthian empire, Rome's most advanced and powerful enemy. In addition, Cappadocia bordered to the northeast with Caucasian Iberia (today known as Georgia), whose mountain passes were the entry route into Anatolia for marauding nomadic tribes from the steppes beyond the Caucasus range. To the east, Cappadocia bordered Armenia, a strategic buffer state that was fought over between Rome and Parthia for centuries. But with just 18 attested regiments, Cappadocia's auxiliary garrison appears to be just one third that of neighbouring Syria's 51 regiments. This is probably due to the fact that no military diplomas for this province have yet been found and other epigraphic evidence is scant. In reality, Cappadocia's auxiliary garrison may have been much closer in size to that of Syria, with as many as double the number of regiments attested.

Moesia Superior's garrison of just 9 regiments was also probably double that, to match its sister province Moesia Inferior's 20. Moesia Superior faced, across the Danube, a barbarian salient between the Roman provinces of Pannonia and Dacia. Called "Free Dacia", it contained one of the most dangerous Sarmatian tribes, the Iazyges, as well as the unconquered part of the Dacian nation.

(3) In addition to the geographical gaps, there are probably gaps in the types of unit deployed. Again the East is the region most in question. For example, we have records of two heavy lancer units (contarii and cataphtactarii) deployed in Pannonia, presumably to counter the strength of the Sarmatians of the Hungarian plain in this kind of heavy cavalry. But we have no records of such units in the East, where they would be vital in combating the Parthians, whose army was mainly composed of cavalry. The standard Parthian battle tactic was to harass and break up the Roman line with hit-and-run attacks by light mounted archers, and then to rout the line with a charge by the cataphractarii. For this same reason, the Romans would have needed a substantial force of mounted archers of their own. But the few alae sagittariae attested in Cappadocia and Syria seem inadequate.

If the auxilia are eventually confirmed as having deployed c440 regiments in the mid 2nd century, then their official strength would likely have exceeded 250,000 men.

Some unresolved issues

(1) Did the auxilia recruit Roman citizens as well as peregrini?
During the Illyrian revolt crisis (6-9 AD, see History, above), when Augustus' government was forced to scrape the barrel to raise sufficient troops, at least 50 auxiliary cohorts were formed composed entirely of Roman citizens. These were men whose status or background was regarded by Augustus as unsuitable for recruitment into the legions: either natural-born citizens of the lowest category including vagrants and convicted criminals, or the thousands of slaves that the government compulsorily purchased and freed. Because they were composed of Roman citizens, these special units were accorded the title civium Romanorum (="of Roman citizens", or c.R. for short). After their initial formation, these cohorts recruited non-citizens like other auxiliary units, but retained their prestigious c.R. title. Template:Hcref

But apart from this exceptional instance, did auxiliary regiments regularly recruit Roman citizens? It appears that they did: there are several documented instances of ordinary legionaries being promoted to higher rank in the auxilia and of serving auxiliary soldiers tranferring to a legion (implying that they were citizens. Most likely, the majority of citizen recruits to auxiliary regiments were the sons of auxiliary veterans who were enfranchised on their fathers' discharge. Many such may have preferred to join their fathers' old regiments, which were a kind of extended family to them, rather than join a much larger, unfamiliar legion (and a few, as we have seen, may have changed their minds later).

(2) Did the auxilia recruit barbari?
In the time of Augustus, there is no doubt that barbari, or natives from outside the empire, were recruited into auxiliary units e.g. the career of Arminius, a member of the Cherusci tribe from the east bank of the Rhine. But in that era, the borders of the empire were still undefined. For example, until Arminius' own victory in the Teutoberg Forest, Augustus aimed to annex the German lands between the Rhine and Elbe rivers. But after the imperial borders stabilised, were barbari still recruited to regular auxilia regiments (as opposed to irregular symmachiarii units)? The consensus is that they were, but there is little evidence of it until the 3rd century. Of the diplomas included in RMD Vols III, IV and V, 65 legibly record the origin of the recipient. Of these none record unequivocal barbari origin. All the certain origins are within the empire. But it is possible that barbari origin is disguised in a few cases: most origins given are the name of a nation or tribe. Where a city is recorded, (e.g. Nicopolis, Moesia Superior - Nis, Serbia) this may be simply the location of the recruitment station where the barbarus recipient signed up. In any event, the sample is too small to be conclusive. If they were admitted to the auxilia, we have no idea what proportion of the troops were barbarian-born in various periods.

(3) Why have no auxiliary diplomas been found dated to later than 203 AD?
No datable auxiliary diplomas have been found beyond 203.This date is very close to 212, when the Antonine decree granted citizenship to the peregrini. One interpretation is that auxiliary diplomas were no longer issued because auxiliary regiments became citizens-only, as were the legions, and barbari were therefore excluded. Against this, is the appearance in the 3rd century of regular auxilia units of clearly barbarian origin e.g. Ala I Sarmatarum and numerus Hnaufridi in Britain. Another possibility is that after 203, metal diplomas were no longer issued for retiring auxiliaries, and replaced by diplomas of biodegradable material such as papyrus or wood. Against this is the fact that metal diplomas continued to be issued throughout the 3rd century by corps other than auxilia that admitted non-citizens: the Praetorian Guard's cavalry arm (equites singulares Augusti), the Rome city police, and the Roman navy. These would have been redundant for peregrini, who were now all citizens. The recipients must therefore be of barbarian origin, even though the origins recorded are within the empire. Again, the origin recorded may disguise true origin.

A further puzzle is why the number of diplomas discovered for the Trajan/Hadrian/Antoninus period (98-161) is far higher than the preceding Julio-Claudian/Flavian period (52-97): c3 times as many diplomas per year. This may indicate a massive rise in the number of auxilia in the Flavian/early Trajan period (69-106): it is possible that the doubling of the auxilia from c125,000 in 23 AD to c250,000 in 138 took place mainly in this period. Many units were upgraded to milliary (double-strength) status in this period and new units founded. However, even a large increase in auxilia numbers could only partly explain the difference in diploma numbers. Another possible factor may be a bureaucratic change e.g. the issuance of metal diplomas free of charge to veterans, instead of charging them for it as previously. After Antoninus, diploma numbers again fall sharply until the final year 203. This may indicate that by this time, many auxiliaries were already Roman citizens, by inheritance from their veteran fathers. In addition, a return to charging for metal diplomas may be at work.

(4) Did auxiliary regiments recruit only in the province they garrisoned, or elsewhere as well?
During the Flavian era (69-96), regiments were routinely stationed in provinces away from their original home provinces. From then, most of their recruitment would likely be derived from local provincials. But the diploma record shows that at least some recruitment continued to be from other provinces, especially the Danubian areas (Raetia, Pannonia, Moesia, Dacia). For example, diplomas RMD 240 and 293 were found in Bulgaria. Their recipients, both of whose origin is given as "Dacian", retired from two regiments stationed in Britain- cohortes II Lingonum and II Gallorum veterana (neither Dacian)- in 127 and 178 respectively. The recipients were thus recruited overseas and returned to their native area (or close to it) after discharge. Epigraphic evidence in Britain shows that some units had an international membership. Recruitment in other provinces implies a centralised recruitment organisation for auxilia for which we have no direct evidence.

(5) Did sagittarii units contain only archers, and did non- sagittarii units contain some archers?
As we have seen, some sagittarii units were equipped in the same way as ordinary alae and cohortes, apart from carrying bows. Also, it would be surprising if ordinary units completely lacked archers, since that would limit their capacity for independent operations. The evidence is ambiguous: not only are some sagittarii units shown carrying other weapons, but some non-sagittarii units are shown employing bows. It is possible that in those sagittarii units that wore normal dress and armour only some sub-units (turmae or centuriae) were composed of archers, while the rest were ordinary troops. Equally, some or even all non-sagittarii units may have contained at least one sub-unit that was archery-capable; alternatively, each sub-unit may have contained some archers.

(6) What proportion of auxiliary cohorts were equitatae i.e. contained a cavalry contingent?
The problem here is that many cohorts not carrying the equitata title have been found to contain cavalry e.g. by discovery of a tombstone of a cavalryman attached to the cohort. As a consequence, the number of cohorts identified as equitatae is a minumum figure, which is expanding as new evidence is found. Only c40% of cohorts attested in the 2nd century are specifically attested as equitatae. But figures given in CAH XI show that 50% of cohorts have been identified as equitatae, and Holder suggests as many as 70% may have been in the time of Hadrian (117-138) and that even this may be an underestimate. Indeed, it is not impossible that almost all cohorts had a cavalry contingent by the early 2nd century. Its own cavalry would obviously give the cohort far more flexibility in the range of operations it could carry out independently. A cohors equitata was in effect a self-contained mini-army.

Notes

^ a: At the end of the rule of Hadrian (138 AD), Rome's standing military forces were a colossal establishment: not far short of half a million men. On the frontiers, 154,000 legionaries (28 legions of 5,500 men each) and c250,000 auxilia (c440 regiments). At Rome, 15,200 troops, made up of 9,200 Praetorian Guards (9 milliary cohorts plus 2,000 equites singulares Augusti) and 6,000 (12 cohorts) cohortes urbanae (City public order guards) and vigiles (fire brigade). In addition, the Roman navy contained probably 30-40,000 marines, sailors and oarsmen, of which 15-20,000 in the Mediterranean fleets at Misenum and Ravenna (contrary to popular belief, Roman warships of this period were not rowed by the forced labour of convicts or slaves, but by volunteer professional oarsmen) and probably the same again in the classis Britannica (English Channel fleet) and the fluvial flotillas on the Rhine and Danube. This adds up to c460,000 regular forces. In addition, substantial numbers of irregular barbarian troops were in the paid service of the empire in that period: we have no idea how many, but we know there were at least 5,500 in Britain alone c175 (surrendered Sarmatian cavalry posted there by Marcus Aurelius). If we multiply this figure by 10 to represent other frontier provinces, it is possible that there may have been 50-60,000 such irregulars at any given time. The early 2nd century establishment of c460,000 regular troops compares to c280,000 at the end of Augustus' rule (14 AD): 125,000 legionaries (25 legions of 5,000 men each) and roughly the same number of auxilia, plus fleets and 6,000 troops at Rome. Most of the growth between 14 and c130 AD was in the number of auxilia, which almost doubled in size. This was a very significant burden on the Roman economy, which was pre-industrial: at least 80% of its inhabitants worked in agriculture. Virtually all the taxes and rents raised by the imperial government were spent on the military: c80% of the imperial budget in c150.This military spending constituted, on one estimate, c2.5% of the empire's GDP, which seems a tolerable burden if compared to the USA, today's global superpower, which spent 3.8% of its GDP on defence in 2006 (18% of the federal budget). But the comparison is misleading. Due to technology, a modern economy is far more productive per capita than the Roman economy: on one estimate, the average American in 1998 was at least 73 times more economically productive, in comparable terms (i.e. in international dollars), than a Roman in the 1st century AD. Therefore, taxes (and compulsory services) to support the Roman military would have taken a much greater share of surplus per capita production i.e. surplus to the subsistence needs of producers. For the average peasant, the taxes and services he was obliged to provide to the military would have represented much of his disposable surplus.

^ b: In 70 AD, all Italians were Roman citizens, as were (probably) the majority of inhabitants of provinces which had seen the most intensive Roman colonisation over the c250 years that they had been under Roman rule: Gallia Narbonensis (southern Gaul), Hispania Baetica (Andalusia, Spain) and Africa proconsularis (Tunisia). In frontier provinces, the proportion of citizens would have been much smaller, though it would have grown over time. Mattingly estimates the citizen body in Britain c.100 AD at c.50,000, less than 3% of the total provincial population. In the empire as a whole, there were 6 million Roman citizens in 47 AD, just 9% of a total imperial population of c70 million (See Peregrinus (Roman) for references).

^ c: The "Roman military confederacy" (a term invented by modern historians) was a defence system built up by the Roman republic over two and a half centuries of warfare on the Italian peninsula. It was a not a confederacy technically, but a series of bilateral treaties between Rome and the other Italian communities with the Romans exercising the dominant role. At the outbreak of the First Punic War in 264 BC, c.150 autonomous Italian states (that is, Italic tribes or Greek and Etruscan city-states) were bound by treaty to Rome. Generally speaking, when an Italian tribe or city-state was finally defeated by Rome, a substantial part of its territory- the best agricultural land- would be annexed to provide land for Roman colonists. The rump state would then be obliged to accept military obligations to Rome in perpetuity. The central, and in most cases the sole, treaty obligation on the socius was to supply to the confederate army, on demand, a number of fully-equipped troops up to a specified maximum each year. The Latin states were otherwise entirely self-governing. The confederacy had massive manpower resources: the Latin allies alone (excluding the Greek city-states) had the capacity to supply up to 375,000 regular troops on the eve of the Hannibalic War. Although Hannibal was never defeated on the battlefield during his long campaign in Italy (218-203 BC), he was eventually forced out of Italy by Rome's crushing numerical superiority. Even after the huge losses inflicted on them by Hannibal in successive battles (in excess of 100,000 dead, not to mention wounded and prisoners), the Romans and Latins were able to field c240,000 men in 212BC. Hannibal's army in Italy never exceeded 40,000 and was less than half that in the later years. N.B. Although called Latins as shorthand by the Romans themselves, most were not members of the Latin tribe strictly speaking, but members of various other Italic tribes and city-states.

^ d: At Cannae, Hannibal exploited the Roman custom of placing Roman cavalry on the right flank of their line, Latin on the left. This meant that three-quarters of their cavalry was on the left flank. By drawing up his heavy cavalry to face the Roman cavalry, he was able to rout the latter easily with a massed charge at the start, ride round behind the Roman line, and surround the Latin cavalry, already engaged by the Numidians, from the rear.

^ e: Massinissa's cavalry played the vital role of neutralising the massive contingent of fellow-Numidians serving under Hannibal.

^ f: A tiny cavalry contingent of 120 was added back to the legion under Augustus. This was the same size as the cavalry contingent of a cohors equitata, a unit a tenth the size of a legion

^ g: Cohorts are first mentioned in the sources as a subdivision of the Latin ala in the period before the Hannibalic War (218-203 BC): at that time their size and structure (if it was standard at all) is unknown. Contemporary legions (known as "Polybian" after the author who described them) were divided into maniples. However, Polybius also mentions cohorts as subdivisions of legions operating in Spain during that war. Such cohorts apparently contained three maniples. However, it is unlikely cohorts became standard subunits until after the Social War (91-88 BC), when they superseded maniples entirely. We have no certain idea of the size of the auxilia at the start of Augustus' sole rule (30BC). But we can make an educated guess. 8 legions (40,000 men) were deployed in the Cantabrian Wars of 29-19BC. Since it was the practice at this time to complement legions with a roughly equal number of auxiliaries on major campaigns (e.g. as in the Illyrian revolt of 6-9AD), it follows that c40,000 auxiliaries (c80 regiments) were probably deployed in N Spain. Given that during the Illyrian revolt roughly half the empire's total auxilia were deployed, and that the Cantabrian Wars were as grave, it is reasonable to assume a similar proportion of auxilia in the latter. This would give a total auxilia empire-wide of c80,000 (c160 regiments). This grew to c125,000 men (c250 units) in 23 AD and c250,000 (c440 units) around 138.

^ h: Some time after Rhoemetalces' death, his kingdom, by then surrounded by the Roman provinces of Moesia (N Bulgaria), Dalmatia (Serbia, Croatia) and Macedonia (Roman province) (Albania, Republic of Macedonia), was annexed by emperor Claudius in 46 AD as the Roman province of Thracia (S Bulgaria, N Greece)

^ i: Roman military diplomas: Diplomas were a certificate to prove the bearer's Roman citizenship. Although they could be issued to anyone, civilian or military, virtually all known exemplars are military discharge diplomas. The recipients are ex-peregrini or barbari who had served in the auxilia, the Roman navy, the Praetorian Guard cavalry and the cohortes urbanae. A matching record known as a constitutio, in the form of a large bronze plate, was lodged in the military archive at Rome (none such has ever been found). Over 800 diplomas from the Principate have been found and over 650 published, providing a rare corpus of Roman documentary material, whose survival is due to its being made of metal, rather than biodegradable material such as papyrus or wood. The diploma consisted of two bronze tablets hinged together. Inscriptions would be engraved on each side of both plates. The plates would then be folded shut and sealed together: the external inscription would be legible without breaking the seals. The internal inscription duplicated the text on the constitutio. The double-inscription and seals were presumably to prevent forgery or alteration. A likely procedure: the holder would take the sealed diploma with him to the province or civitas (county) he intended to retire in. He would then present the diploma to the keeper of archives either at the provincial governor's headquarters (or perhaps at his local civitas offices). The archivist would break the seals and check that the data on the internal inscription matched the external one. If it was in order, he would then enter the diploma holder's name onto the register of resident Roman citizens, thereby ensuring he could benefit from the substantial advantages of that status (especially exemption from the poll tax). A particular advantage of diplomas for historians is that they record the names of several units serving in the same province at the same time, as diplomas were issued in batches: thus a single diploma may yield the names of as many as 25 units. As regards the recipient of the diploma, the following details are recorded: name of beneficiary and name of his father; names of beneficiary's wife and children also granted citizenship; military rank; origin (nation, tribe or city); regiment; province and date of issue.

^ j: Of a legion's 6 tribuni militum, all were equestrians save the tribunus laticlavius, the legion's second-in-command, who was of senatorial rank.

^ k: The Batavi (the name is believed to derive from West Germanic beter (="better", i.e. "superior men") moved into the Betuwe in the late 1st century BC. The previous inhabitants of the area were Celtic-speaking Gauls, as evidenced by the two Latinised Celtic names for their chief town: Batavodurum and Noviomagus (Nijmegen, Neth). It is unclear whether the existing inhabitants were simply subjugated with the Batavi forming a ruling elite, or the existing inhabitants simply displaced. For this reason it is also uncertain whether the Batavi remained Germanic-speaking or adopted the Belgic Gallic tongue of the indigenes. Batavi military exploits had included swimming across the river Medway in Kent, England during the Roman invasion of Britain in 43 AD. Their action was decisive in the defeat of the British army ranged on the other side. It is uncertain how they were able to accomplish this feat. The late 4th century writer on Roman military affairs Vegetius mentions soldiers using reed rafts, drawn by leather leads, to transport equipment across rivers. But the sources suggest the Batavi were able to swim across rivers actually wearing full armour and weapons. This would only have been possible by the use of some kind of buoyancy device: Ammianus Marcellinus mentions that the Cornuti regiment swam across a river floating on their shields "as on a canoe" (357 AD). Since the shields were wooden, they may have provided sufficient buoyancy.

^ l: British auxiliary units attested in the 2nd century: Alae: I Brittonum c.R. and I Flavia Britannica, both stationed in Pannonia. Cohortes: I Aelia Brittonum (Noricum); I Augusta Brittonum Nerviana (Dacia); I Britannica c.R. (Dacia); I Flavia Brittonum (Moesia Sup.); II Augusta Brittonum Nerviana (Dacia); II Britannorum c.R. (Dacia); II Brittonum equitata (Mauretania); II Brittonum milliaria (Germania Inf); III Britannorum (Raetia); III Brittonum veterana (Moesia Sup.); VI Brittonum (Germania Inf). Most British units were thus stationed on the Danube, especially Dacia.

^ m: Some authors (e.g. Cary & Scullard, Hassall) have argued that in practice the citizenship rule was widely ignored and large numbers of non-citizens admitted to the legions. But their only hard evidence for this comes from the East after 70 AD: here there are indications that the rule was bent to admit the illegitimate sons of legionaries. From Augustus until the time of Septimius Severus, legionaries were forbidden to marry during their term of service. In practice many had stable relationships and brought up families. Their sons, brought up near military bases and among soldiers, would make ideal recruits. But because they were illegitimate, they could not inherit their fathers' citizenship. Most likely, the rule was generally circumvented in their case, especially in provinces where the available pool of Roman citizens was not large enough to satisfy the local legions' recruitment needs (as in Britain: cf. Mattingly op cit 168). But this exception does not invalidate the central rule. The sons of legionaries were after all of Roman blood, and their non-citizenship was due only to a legal technicality. N.B. There is an exceptional group of legionary diplomas issued to retiring soldiers of legions I Adiutrix and II Adiutrix in 68 and 70 AD respectively, dates when these legions were constituted. This implies the retirees were non-citizens. The explanation for this anomaly seems to be the emergency political conditions at that time: the Civil War of 68-9 and the revolt of Civilis 69-70. These two legions were hastily formed from naval marines from the fleets at Ravenna and Misenum, many of whom would have been non-citizens: the Roman navy appears to have admitted both citizens (freedmen) and peregrini. The diplomas evidently record the discharge of naval personnel recruited in the 40's and due for retirement after their 25-year term of service. But again, this was an exceptional case: no later legionary diplomas have been found. It cannot therefore be used to support the view that non-citizens were routinely admitted to legions.

^ n: It has been argued that the lorica segmentata was used by auxiliaries also. But there is no firm evidence for this. Traces of this type of armour have been found in forts in Raetia from a time when no legions were stationed in the province. But these may simply have been left behind by legionaries on temporary detachment. Furthermore auxilia are nowhere depicted wearing such armour. Testing of replica lorica segmentata by re-enactors has shown that it is more uncomfortable and restricting than mail and can only be worn for short periods. On the plus side, tests have shown that it provides more effective protection against missiles and other blows than other types of armour.

^ o: Origin of the 32 sagittarii units attested in mid 2nd century: 13 Syrian, 7 Thracian, 5 from Asia Minor, 1 from Crete and the remaining 6 of other or uncertain origin.

^ p: The Vindolanda tablets are believed to relate to the cohortes I Tungrorum (mainly), III Batavorum and IX Batavorum. 573 have been published to date. The tablets survived organic decomposition because they were deposited in anaerobic environments (such as waterlogged soil).

^ q: In general, legions took the lead in big construction projects because, being much larger units than auxiliary regiments, they contained most, if not all, of the army's leading constrcution experts such as engineers, architects and master craftsmen. Auxiliary regiments had their own craftsmen, but on a lower level and smaller scale: independently, therefore, they could only carry out smaller projects such as individual buildings. For the construction of Hadrian's Wall, there is only inscription evidence for the participation of the 3 legions then in Britain: II Augusta, VI Victrix, and XX Valeria Victrix. But given the enormous manpower requirements of the project, and the fact that auxilia by then outnumbered legionaries by 2.5 to 1 in Britain, it can be safely assumed that auxiliaries were heavily involved. A possible explanation for lack of auxilia evidence on the Wall is that they were given tasks, such as excavating the huge fossa (="ditch") behind the Wall, which did not involve the use of stones on which graffiti could be engraved.

^ r: Judging by the numeration of such units as survived into the 2nd century, the following types of citizen units were raised to face the Illyrian crisis: at least 33 cohortes voluntariorum (="volunteers". These were the slaves purchsed and freed by the government. The deal offered them no doubt promised their freedom in return for satisfactory service); at least 6 ingenuorum ("free-born"); 3 Campestris ("rural"); 2 classica ("naval"); 2 simply civium Romanorum; 2 Italica; 1 Cisipadensium; 1 Campanorum. After Augustus' time, many other auxiliary regiments were granted the c.R. title when the entire unit was granted Roman citizenship by emperors "on the spot" as reward for exceptional service during major campaigns. Such a grant would only apply to soldiers serving at the time, and not to later recruits to the regiment, but the regiment would retain the c.R. title in perpetuity

See also

• List of Roman auxiliary regiments
• Structural History of the Roman military
• Roman Army
• Auxiliaries in Britain (Roman military)

External links

• Roman Military Diplomas Online
• Batavian auxiliaries re-enactors
• List of auxiliary units in Britain
• Vindolanda Tablets Online