Roman Legions

Origins

The legion was Rome's answer to almost every enemy for seven hundred years. The word legio originally meant "levy," the whole body of citizens called up for war. In the early Republic, the legion is thought to have fought as a phalanx. By the fourth and third centuries BC it had changed into the more flexible manipular legion, with three lines of heavy infantry, the young hastati in front, the principes behind them and the veteran triarii at the rear. Around 100 BC, in changes traditionally linked to the general Gaius Marius, the army began to recruit poor volunteers and to be organized in cohorts. Under Augustus the legions became a permanent, professional force.

Organization & Training

The legion of the Empire was a standing formation of Roman citizens, roughly five thousand men. It was divided into ten cohorts, each made up of six centuries of about eighty men led by a centurion, with a larger first cohort. Each legion had a number, a name, and an eagle standard that its men would die to protect. A professional officer class ran it, and constant drill made complex battlefield maneuver a reflex. Service eventually ran twenty-five years; the reward was land or money on discharge. Provincials in the auxiliary regiments that fought alongside the legions earned Roman citizenship itself at the end of their service.

Weapons & Equipment

Legionary equipment changed over the centuries, but the system held. A volley of the Roman Pilum wrecked the enemy line, and then the Roman Gladius, used behind the big Roman Scutum shield, did the close work, with the Roman Pugio dagger as a sidearm. Legionaries wore mail and, from the early first century AD, the Roman Lorica Segmentata. In the later Empire the longer Roman Spatha replaced the gladius. Each legion also had artillery such as the Roman Ballista, and engineering tools mattered as much as weapons. On campaign a legion built a fortified camp at the end of each day's march, and legions could bridge rivers, besiege cities and build roads across a continent.

Notable Actions

The conquest list is the map of the Roman Empire: Italy, Spain, Carthage, Greece, Gaul, Egypt and Britain. In the Punic Wars Rome survived Hannibal's crushing victory at the Battle of Cannae in 216 BC and went on to destroy Carthage in 146 BC. Julius Caesar's legions conquered Gaul in the 50s BC, and Claudius began the conquest of Britain in AD 43. Defeats were absorbed by an institution built to outlast any battle. When three legions were destroyed at the Battle of Teutoburg Forest in AD 9, their numbers were never used again, but the frontier held on the Rhine.

Legacy

In the late Empire, legions became smaller and the army relied more on cavalry and on barbarian allies. The Western Empire fell in 476, but the eastern Roman army carried on in the Byzantine Empire. The legions' deeper legacy is organizational. Ranks, standards, pensions, written drill and the very idea of a professional national army all look back to them. Western military vocabulary still speaks Latin: legion, cohort, centurion, decimation and many more words come straight from the Roman army.

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