Roman naming conventions
Roman naming practices varied greatly over the centuries between the founding of Rome to the early Middle Ages. However, the practice of the elite during the period between the mid-Republic and the early Empire has come to be seen as the classical Roman naming convention. This is likely to be because this period provides good evidence of naming practices of the best documented class in the best documented Roman period.
By the end of the Republican era, a name for an aristocratic male citizen comprised three parts (tria nomina): praenomen (given name), nomen (or nomen gentile or simply gentilicium, being the name of the gens or clan) and cognomen (name of a family line within the gens). Sometimes a second or third cognomen, called agnomen, was added. The nomen, and later, cognomen were virtually always hereditary. During the Imperial period, the number and options for elements within a name considerably increased. The naming conventions for the later period grew out of a desire to indicate status, connections and ancestry, in a way that was much more wide-ranging than could be shown by the tria nomina.
During the Empire, superficially the naming conventions appear to dissolve into anarchy. In fact, this was not the case as new conventions developed, which were themselves internally coherent. A wide range of naming models developed.
Females were officially known by the feminine form of their father's nomen gentile, followed by the genitive case of their father's (husband's if married) cognomen and an indication of order among sisters. By the late Roman Republic, women sometimes also adopted the feminine of their father's cognomen. A woman usually did not have the praenomen and agnomen, unless the parents chose to give her those.
Early History 
In the early regal period of Rome, it appears that people were at first referred to by one name (e.g., Romulus, Manius). As Rome grew in area and population, a second, family name came into use. By the earliest days of the Republic, every member of a household had at least two names—praenomen, and the genitive form of the pater familias (father of the family) name, which became a fixed and inherited nomen (name).
This binomial nomenclature was unique among Indo-European languages of that era. Also, the core part of the name (nomen) was the inherited gens name, not the given name (praenomen). This is probably why so few different praenomina were used.
Later in the Republic a cognomen was added to distinguish families within a gens, as the importance of the gens grew and the size of voting tribes required this differentiation. Thus patricians (nobility) commonly had three names (Tria Nomina). Although this system dates to the later 5th century BC, it was slow to take root, as it does not appear in official documents until the late 2nd century BC and was not common until the time of Sulla, right before the Empire. It was adopted even more slowly by non-patricians; the first examples of cognomina for plebeians date to c. 125 BC and it was not popular for another century.
Mid/late Republic to the early Empire 
Although the tria nomina convention is often seen as the classic Roman naming convention, in fact it was only predominant from the mid-republican period to the early Empire, and then only amongst the elite. It is likely that it is only thought of as the classic naming convention because it was typical of the best documented class in the best documented Roman period.
Praenomen, Nomen, Cognomen 
The praenomen, equivalent to given names today, was chosen by the parents (often with the pater familias naming male infants after himself). There was, however, a very limited selection of praenomina, such as Gaius, Gnaeus, Marcus, Quintus, Publius, Tiberius, and Titus. As a result, men from a given family often have identical names for generations. It was therefore necessary to use other names (cognomen and later, agnomen) to distinguish between individuals. Only intimates would use the praenomen.
The second name, or nomen gentile (usually simply nomen), rarely gentilicium, is the name of the gens (the family clan), in masculine form for men. The original gentes were descended from the family groups that settled Rome. These eventually developed into entire clans, which covered specific geographic regions. As the area of Rome expanded, the number of tribes also expanded. This meant that not all tribes were from original settlers. Some were named for Etruscan or Sabine families, while others were from local tribes or from major geographical features, such as rivers. Well-known nomina include many of the familiar names of ancient Rome, such as Aemilius, Claudius, Cornelius, Domitius, Julius, Junius, Pompeius, Antonius, Didius and Valerius.
The third name, or cognomen, began as a nickname or personal name that distinguished individuals with the same names. Cognomina do not appear in official documents until around 100 BC. Often the cognomen was chosen based on some physical or personality trait, sometimes with ironic results: Julius Caesar's cognomen, in one interpretation, meant hairy (cf. etymology of the name of Julius Caesar) although he was balding, and Tacitus' cognomen meant silent, while he was a well-known orator. However, from the Republican era, many cognomina were no longer nicknames, but instead were passed from father to son, serving to distinguish a family within a gens (and frequently requiring an agnomen to distinguish people of the same family if they shared praenomen as well as nomen and cognomen).
Some males had a cognomen that ends in -anus, which was adapted from and commemorated a nomen, sometimes their maternal family or—if they were adopted—their original paternal family. For instance, Vespasian's nomen (Flavius) came from his father's nomen. His cognomen (Vespasianus), on the other hand, was derived from his mother's nomen, Vespasia. Others had cognomina that were derived not from the nomen, but the cognomen of their mothers' families. For instance, Caracalla's maternal grandfather was Julius Bassianus, but Caracalla's cognomen was not Julianus, but rather Bassianus as well.
When a man was adopted into another family, he would take on his adoptive father's names (excluding the praenomen). If he chose to, he could turn his original nomen into an additional cognomen that followed his newly gained names. For example, these adoptees incorporated into their new names their adopted family's nomen and cognomen, and also kept their birth family's nomen:
- Publius Cornelius Scipio Aemilianus: Publius was adopted into the Cornelii Scipiones, but was born an Aemilius.
- Mamercus Aemilius Lepidus Livianus: Mamercus was born a Livius, adopted into Aemilii Lepidi.
Not all adoptees chose to identify their birth families. For instance, as an adult, Augustus did not use his cognomen Octavianus (shortened to Octavian), since the gens Octavia was not nearly as esteemed as the Julii. (See also: Adoption in Rome.)
Additional elements 
After the cognomen became hereditary and lost its function as a nickname, a second nickname, or agnomen, was appended to the name after birth—usually not immediately—to signify some personal characteristic or accomplishment. A common agnomen was Pius, for someone who displayed virtues like honesty, reverence to the gods, or devotion to family and state. Superbus ("Proud") and Pulcher ("Handsome") were also examples of agnomina.
Unlike the nomen and cognomen, an agnomen was usually not inherited unless the son also had the same attribute or did the same deeds, although some victory agnomina like Augustus ("Majestic") and Germanicus ("the German (Conqueror)") eventually became handed down as additional cognomina.
It may also have been the case that some families used an agnomen in order to distinguish individuals, especially when there was a famous cognomen which they wanted all their sons to be able to bear. This is evident in the Valerius Messalla family tree where the following names are to be found:
- Marcus Valerius Messalla Niger (consul in 61 BC)
- Marcus Valerius Messalla Corvinus (64 BC–AD 8)
- Marcus Valerius Messalla Messallinus (consul AD 3)
- Marcus Valerius Messalla Barbatus (11 BC–AD 20/21)
- Marcus Valerius Messalla Corvinus (consul in AD 58)
Filiation and Tribe 
The full form of a Roman name, used in official records, included the praenomen and nomen, followed by a "filiation", the name of the voting tribe in which the person was enrolled, and finally the cognomen and agnomen, if any. In some instances the place of a person's residence might also be added.
The filiation was a traditional element of a Roman name, usually giving the praenomina of the person's father and grandfather. A typical example written in full would be Marcus Aemilius Quinti filius Marci nepos Lepidus, although this would normally be abbreviated to M. Aemilius Q. f. M. n. Lepidus. In this example, Quinti filius means "son of Quintus", and Marci nepos means "grandson of Marcus". Sometimes the filiation would be extended to pronepos (great-grandson) and abnepos (great-great-grandson). Filiation was also used for daughters, in which case filius and nepos would be replaced by filia (daughter) and neptis (granddaughter). The same abbreviations were used for both sons and daughters. For a list of praenomina and their abbreviations, see praenomen.
The tribus, or "tribe," was a geographically-determined voting assembly, not an ethnic designation, although certain social and ethnic groups sometimes were concentrated in particular tribes. All Roman citizens were enrolled in one of the voting tribes, whose number was fixed at thirty-five by the late Republic. The tribe in which a man was enrolled was generally determined by the location of his principal residence, but if he changed residence he did not also change tribes.
Precisely when it became common to include the name of a man's voting tribe as part of his full name is unknown. The name of the tribe normally follows a man's filiation and precedes his cognomina, suggesting that it was an early development. However, it is found with much less frequency than the other parts of the name, so the custom of including it does not seem to have been deeply ingrained in Roman practice. As with the filiation, it was common to abbreviate the name of the tribe. For the names of the thirty-five tribes during the late Republic, see list of Roman tribes.
The eldest son usually carries on his father's name. Younger sons are typically named for a grandfather or uncle. The proliferation of men carrying the same name can complicate prosopography; for instance, in the early 1st century BC, three prominent men were named Lucius Valerius Flaccus: the consul of 100 BC, the suffect consul of 86 BC, and the latter's son, who was defended by Cicero (Pro Flacco).
Examples of Tria Nomina 
Analysis of an example complete name: Marcus Aurelius Lucii f. Quinti n. tribu Galeria Antoninus Felix, domo Caesaraugusta.
|Aurelius||nomen gentile||he belonged to gens Aurelia (the Aurelii)|
|Lucii f(ilius)||patronimicus||son of Lucius|
|Quinti n(epos)||grandparent||grandson of Quintus|
|tribu Galeria||tribe||a tribe from Galleria, a region of Hispania|
|Antoninus||cognomen||he belonged to Antonini branch of the clan|
|Felix||agnomen||"the Fortunate", a nickname|
|domo Caesaraugusta||residence||ancient Zaragoza in Hispania|
A Roman man could be referred to in several ways: by his praenomen and nomen; by his nomen or cognomen standing alone; by his nomen and cognomen; or by his praenomen and cognomen. Which of these was used typically depended on how many other people might be referred to by the same name or combination of names. In the early Republic the nomen was often sufficient to distinguish people, but by imperial times a person's various cognomina were usually more distinctive. "Marcus Livius Drusus" would typically be referred to as "Marcus Livius" or simply as "Drusus", although both "Livius Drusus" and "Marcus Drusus" could also be used.
The tendency to omit one or more parts of a person's name can create problems for modern scholars. Often several different people shared the same name, or names that differed in only one element. In many cases, we no longer have the context to know which person was actually meant.
63 BC: Augustus is born as Gaius Octavius
- Gaius Octavius Gaii filius
- Gaius of the gens Octavia, son of Gaius
44 BC: Julius Caesar dies. In his will he adopts Gaius Octavius. See Adoption in ancient Rome.
- Gaius Iulius Gaii filius Caesar Octavianus
42 BC: Julius Caesar is deified, prompting a change in Gaius Octavianus' name.
- Gaius Iulius Divi filius Caesar Octavianus
31 BC: Gaius Octavianus is declared imperator by the army
- Imperator Gaius Iulius Divi filius Caesar Octavianus
27 BC : The Roman Senate grants the title Augustus. Gaius Octavianus assumes his official regnal name.
- Imperator Caesar Divi filius Augustus
- Imperator Caesar the August, son of the Deified
Foreign names 
As Rome conquered territories beyond the Italian peninsula, many foreign names were introduced. Discharged auxiliary soldiers and others gaining Roman citizenship could, and many did, continue to use at least a portion of their former names. Most were of Greek or Etruscan origin, while others came from regions that were brought under Roman influence.
A freedman customarily took his former owner's praenomen and the nomen of his master's gens, retaining his former name as a cognomen. For instance, a former slave named Chrysogonus freed by Lucius Cornelius Sulla acquired the name Lucius Cornelius Chrysogonus.
Female names 
Roman women usually had no praenomen and were known only by the feminine form of their father's nomen. If further description was needed, the name was followed by the genitive case of her father's cognomen or, after marriage, of her husband's. Hence, Cicero speaks of a woman as "Annia P. Anni senatoris filia" (Annia the daughter of P. Annius the senator). By the late Republic, women also adopted the feminine form of their father's cognomen. Aquilia Severa was the daughter of Aquilius and married a Severus (in her case, both of her names are derived from nomina). Feminized cognomen was often made a diminutive, e.g. Augustus's third wife Livia Drusilla was the daughter of Marcus Livius Drusus.
If only two daughters survived, they could be distinguished as major and minor. Mark Antony's daughters were Antonia Major (paternal grandmother of the emperor Nero) and Antonia Minor (mother of the emperor Claudius, maternal great-grandmother of the emperor Nero). If a family had more than two daughters, they were distinguished by ordinal numbers: Cornelia Quinta, the fifth daughter of a Cornelius. The epithets of Major and Minor (or the Elder and the Younger) also served to distinguish between daughters and mothers of the same name, e.g., Agrippina the Younger and Julia the Younger, respective daughters of Agrippina the Elder and Julia the Elder. Multiple women with the same nomen were sometimes distinguished by nicknames or "inverted" praenomina (that is, praenomina that were treated as cognomina).
Thus, the daughter of Lucius Julius Caesar was simply called "Julia". The daughters of Marcus Antonius were typically referred to as "Antonia Major" and "Antonia Minor". A daughter of Lucius Aemilius Paullus could be called "Tertia Aemilia", or "Aemilia Tertia" (with an inverted praenomen). Both nomen and cognomen were used by Caecilia Metella, the daughter of Lucius Caecilius Metellus.
Names under the Empire 
During the Empire, superficially the naming conventions appear to dissolve into anarchy. In fact, this was not the case: new conventions developed, which were themselves internally coherent.
Binary nomenclature and polyonomy 
Under the "High Empire", the new aristocracy began adopting two or more nomina - a practice which has been termed 'binary nomenclature'. This arose out of a desire to incorporate distinguished maternal ancestry in a name or, in order to inherit property, an heir was required by a will to incorporate the testator's name into his own name. For example, the suffect consul of AD II8/9, Gaius Bruttius Praesens Lucius Fulvius Rusticus, has a name which is composed of two standard sets of tria nomina: he was the natural son of a Lucius Bruttius, and added the nomina of his maternal grandfather, Lucius Fulvius Rusticus, to his paternal nomina.
In order to reflect an illustrious pedigree or other connections, the aristocracy expanded the binary nomenclature concept to include other nomina from an individual's paternal and maternal ancestry. There was no limit to the number of names which could be added in this way (known as polyonomy), and, for example, the consul of 169 AD, (usually called Q. Sosius Priscus) had 38 names comprising 14 sets of nomina reflecting a complex pedigree stretching back three generations.
Cognomen replaces praenomen 
The praenomen, even under the classic system, had never been particularly distinctive because of the limited number of praenomina available. Between the late Republic and the 2nd century AD, the praenomen gradually became less used and eventually disappeared altogether. Even among the senatorial aristocracy it became a rarity by about 300 AD. In part this came about through a tendency for the same praenomen to be given to all males of a family, thereby fossilizing a particular preaenomen/nomen combination and making the praenomen even less distinctive e.g. all males in the emperor Vespasian's family (including all his sons) had the praenomen/nomen combination Titus Flavius:
- grandfather: Titus Flavius Petro
- father: Titus Flavius Sabinus (married Vespasia Polla)
- elder brother: Titus Flavius Sabinus, whose son was Titus Flavius Sabinus and grandsons were Titus Flavius Sabinus and Titus Flavius Clemens.
- Titus Flavius Vespasianus, emperor, known as Vespasianus (married Flavia Domitilla)
- eldest son: Titus Flavius Vespasianus, emperor, known as Titus
- youngest son: Titus Flavius Domitianus, emperor, known as Domitianus
The cognomen, as in Vespasian's family, then assumed the distinguishing function for individuals; where this happened, the cognomen replaced the praenomen in intimate address. The result was that two names remained in use for formal public address but instead of praenomen + nomen, it became nomen + cognomen.
Constitutio Antoniniana 
With the Constitutio Antoniniana in 212, the emperor Caracalla granted Roman citizenship to all free inhabitants of the empire. It had long been the expectation that when a non-Roman acquired citizenship he, as part of his enfranchisement, took on a Roman name. With the mass enfranchisement of 212, the new citizens adopted the nomen ‘’Aurelius’’ in recognition of Caracalla’s beneficence (the emperor’s full name was Marcus Aurelius Severus Antoninus Augustus, with Aurelius as the nomen). ‘’Aurelius’’ quickly became the most common nomen in the east and the second most common (after ‘’Julius’’) in the west. The change in the origins of the new governing elite that assumed control of the empire from the end of the 3rd century can be seen in their names: 7 of the 13 emperors between Gallienus and Diocletian bore the name ‘’Marcus Aurelius’’
Although praenomina were not adopted by the new citizens, reflecting the pre-existing decline amongst “old” Romans, in the west the new names were formulated on the same basis as the existing Roman practices. In the east, however, the new citizens formulated their names by placing ‘’Aurelius’’ before versions of their non-Roman given name and a patronymic. Ultimately, the ubiquity of ‘’Aurelius’’ meant that it could not function as a true distinguishing nomen, and became primarily just a badge of citizenship added to any name.
Traditional nomen replaced 
Although a nomen would long be required for official purposes, and, in isolated corners of the empire and in parts of Italy, its usage would persist into the 7th century, the nomen was generally omitted from the name (even of emperors) by the 3rd century.
Two factors encouraged its frequent non-use. Firstly, the cognomen increasingly became the distinguishing name and general name of address. As a result, “New Romans” and, under their influence, “old Romans” too, either dropped the nomen from their name or, in some cases, treated the nomen as a praenomen.
Secondly, with the nomen becoming an increasingly fossilized formality, non-Italian families, even those who had acquired citizenship and a nomen prior to 212, began to ignore their nomen. When a nomen was required for official purposes they would simply put the default nomen of ‘’Aurelius’’ in front of their name, rather than use their actual nomen.
See also 
- Salway 1994, p. 124.
- Lawrence Keppie, Understanding Roman Inscriptions (Routledge, 1991), p. 19 online.
- Salway, p.145
- Salway, p.131
- Salway, p.132
- Flower, Harriet (ed.). The Cambridge Companion to the Roman Republic. p. 119. ISBN 0-521-00390-3.
- Salway, p.130
- Salway, p.133
- Salway, p.134
- Salway, p.136
- Salway, p.135
- Salway, Benet (1994). What's in a name? A survey of Roman onomastic practice from c.700 b.c. to 700 a.d. (Journal of Roman Studies, Vol.84, pages 124-145).
- Roman Nomenclature
- Names and Naming Practices of Regal and Republican Rome (by Meradudd Cethin)
- Behind the Name: List of Ancient Roman Derived Names
- Choosing a Roman name (NovaRoma)
- Cambridge Latin Course, University of Cambridge Press 2004, ISBN 0-521-78230-9
- Liberati, Anna Maria and Bourbon, Fabio (2005), Barnes and Noble Press, ISBN 0-7607-6234-1