‘Legion’ derives from the Latin legio, which itself comes from the verb legere, meaning ‘to choose’ or ‘to levy’. The legion represented the muster of Rome’s citizens in times of war. It appeared in English in the Middle Ages, and came to mean a large body of soldiers, or simply many people or things.
In 1611, Shakespeare wrote in Cymbeline: ‘The Romaine Legions, all from Gallia drawne,/ Are landed on your Coast.’ In the Gospel of Mark, just before Jesus Christ exorcises a multitude of demons from a possessed man, they identify themselves to him: ‘My name is Legion,’ they say, ‘for we are many.’
During the American War of Independence, a Loyalist ‘British Legion’ would fight on behalf of the Crown. Today, it might be said of someone well-regarded that they have a ‘legion of admirers.’
The great strength of the Roman legion was its tactical exibility, with its legionaries fighting in 30 maniples (or later ten cohorts) that could manoeuvre and fight independently of one another.
During the Roman Republic, the legion of 4,200 was drawn up in three battle lines: 1,200 hastati, each armed with pilum (javelin) and gladius (sword), in the front; 1,200 principes, each also bearing pilum and gladius, forming the second line; and 600 spear-wielding triarii in the rear. Ahead of them all fought 1,200 skirmishing velites armed with swords and javelins.
Later, in the 5,000-strong professional legion of the Roman Empire, the old distinctions between the hastati, principes, and triarii were done away with. To these were attached 120 cavalry to conduct reconnaissance and deliver messages.
Overall command of the legion rested in the hands of a legate, with assistance given by the tribunes and centurions who served beneath him. In its early 1st-century AD heyday, the Empire was defended by 28 such legions.
This article appeared in issue 72 of Military History Monthly.