Borders of the Roman Empire

Map of all the territories once occupied by the Roman Empire. The lands in cyan and magenta represent those whose conquest is doubtful. Archeological evidence shows however that the Dortmund area in Germany was part of the Empire in the beginning of the first century AD. Yellow lines are Limes

The borders of the Roman Empire, which fluctuated throughout the empire's history, were a combination of natural frontiers (most notably the Rhine and Danube rivers) and man-made fortifications (limes), which separated the lands of the empire from the "barbarian" countries beyond.

The limes

The limes that protected the Empire from German raids.

A limes was a border fortification system of the Roman Empire. The Latin noun limes had a number of different meanings: a path or balk delimiting fields, a boundary line or marker, any road or path, any channel, such as a stream channel, or any distinction or difference. Hence it was utilized by Latin writers to denote marked or fortified frontiers. The name given to proper Walls was vallum, which might have represented a border. In Brittania the Empire built two walls one behind the other, for Mauretania there was a single wall with forts on both sides of it. In other places, such as Syria and Arabia Petraea, there wasn't a continuous wall; instead there was a net of border settlements and forts occupied by the Roman army. In Dacia, the limes between the Black Sea and the Danube were a mix of the latter and the wall defenses: the Limes Moesiae was the conjunction of two, and sometimes three, lines of vallum, with a Great Camp and many minor camps spread through the fortifications.

Location of Hadrian's Wall and the Antonine Wall in Scotland and Northern England.

The northern borders

In continental Europe, the borders were generally well defined, usually following the courses of major rivers such as the Rhine and the Danube. Nevertheless those were not always the final border lines; the province of Dacia, modern Romania, was completely on the far side of the Danube, and the province of Germania Magna, which must not be confused with Germania Inferior and Germania Superior, was the land between the Rhine, the Danube and the Elbe (Although this province was lost three years after its creation as a result of the Battle of Teutoburg Forest).

In Great Britain both Hadrian and Antonius Pius built defences to protect the province of Britannia from the Caledonians, given that, from their point of view, it was a waste of resources to conquer Caledonia (broadly corresponding to modern Scotland). Hadrian's Wall, constructed in 122 held a garrison of 10,000 soldiers, while the Antonine Wall, constructed between 142 and 144, was abandoned by 164 and briefly reoccupied in 208.

The Pannonian Limes

The eastern borders

Main article: Roman-Persian Wars

The eastern borders changed many times, of which the longest lasting was the Euphrates river, eventual to be left behind as the Romans defeated their rivals, the Parthians, with the march on their capital, Susa in 115. The Parthians were a group of Iranian peoples that ruled most of Greater Iran that is in modern day Iran , western Iraq , Armenia and the Caucasus. In 115 Hadrian decided that it was in Rome's interest to re-establish the Euphrates as the limit of its direct control. Hadrian returned to the status quo ante, and surrendered the territories of Armenia, Mesopotamia, and Adiabene to their previous rulers and client-kings and didn't attempt to romanize the Parthian Empire.A final war against the Parthians was launched by the Emperor Caracalla, who sacked Arbela in 216. After his assassination, his successor, Macrinus, was defeated by the Parthians near Nisibis. In exchange for peace, he was obliged to pay for the damage caused by Caracalla.

The southern borders

At its greatest extent, the southern border was the deserts of Arabia and Sahara, that represented a natural barrier to prevent expansion. The Empire controlled the Mediterranean shores and the mountains opposing it. However the Romans attempted twice to occupy effectively the Siwa Oasis (and failed) and controlled the Nile many miles into Africa up to the modern border between Egypt and Sudan.

See also

• Limes
• Roman Empire
• Antonine Wall
• Hadrian's Wall

References

• De Agostini (2005). Atlante Storico De Agostini. Novara: Istituto Geografico De Agostini. ISBN 88-511-0846-3.
• Camer, Augusto and Renato Fabietti. Corso di storia antica e medievale 1 (seconda edizione). ISBN 88-08-24230-7.
• Grant, Michael (1994). Atlas of Classical History (5th edition). New York: Oxford Univ. Press. ISBN 0-19-521074-3.
• Scarre, Chris (1995). The Penguin Historical Atlas of Ancient Rome. London: Penguin. ISBN 0-14-051329-9.