The Roman Legion

Imperial Roman legionaries in tight formation, a relief from Glanum, a Roman town in what is now southern France that was inhabited from 27 BC to 260 AD

The Roman Empire was gigantic by the time of Emperor Trajan’s death in A.D. 117. From Britain to Syria, from the River Rhine to northern Africa, Roman governors ruled huge areas of the ancient world. The key to Roman military success were the Roman legions. A legion was the military organization, originally the largest permanent organization in the armies of ancient Rome. The term legion also denotes the military system by which imperial Rome conquered and ruled the ancient world. Each Roman legion had many soldiers accompanied by skilled cavalrymen. Roman soldiers were tough, loyal, dedicated, highly disciplined, and skillful fighters. With their large shields, deadly spears, lethal javelins, and vicious stabbing swords, they conquered many diverse people groups by employing conventional and innovative battle tactics during combat.

Rome’s Rise and Fall

Rome was founded in 753 B.C. before it became a republic in 509 B.C. Rome grew gradually through the centuries and eventually conquered all its Italian neighbors. While the Romans’ power and confidence enlarged, so did their ambitions to govern beyond Italy. In the third century B.C, the Romans were warring against the Carthaginians, a North African people equipped with a superior navy and a great army. After three titanic wars, the Romans finally emerged victorious over Carthage in 146 B.C. Romans brought Sicily, Corsica, Sardinia, and Spain under their control before they turned eastward to conquer Greece and Asia Minor. Julius Caesar, the greatest of all Roman commanders, conquered Gaul, located in modern France, between 58 and 50 B.C. Later, Emperor Claudius annexed Britain in A.D. 43. During the subsequent decades, the Roman legions added more territories to Rome before it began to decline partly because of barbarian integration into the Roman army and the gigantic geographical size of the Roman Empire.

Rome was first a republic, ruled by officials called consuls. Eventually, after several bitter civil wars, the Roman Republic became an empire. The first emperor was Augustus (27 B.C to A.D 14). His Roman successors lasted until the fifth century A.D. when the western part of the Roman Empire fell to the barbarian invasions, while the eastern part of the Roman Empire continued for almost 1,000 years.

Roman Weapons and Armor

Roman legionnaire soldiers were equipped with many weapons. The most useful of their weapons were the short stabbing swords called the gladius. The best gladius swords were made in Spain. Although the Roman gladius was shorter than the Celtic slashing swords and other barbarian swords, this Roman sword was a pointed, dubled-edged weapon that was easy to handle for thrusting, cutting, and stabbing the enemy. The gladius was perfectly designed for close-quarter combat with enemy.

Roman soldiers used two kinds of spears. The first was a light spear with a leaf metal head, which was designed for trusting deep into the enemy. The second was pilum or javelin throwing spear, which was shorter, but much heavier. The pilum was designed to bend when it hit the enemy to prevent the enemy from throwing the weapon back.

To protect themselves, legionnaire soldiers wore metal helmets, dressed in strong body armor, and carried large shields. Helmets were made of iron, bronze, and brass. They varied in shape and size, but were primarily designed to protect the soldiers’ necks, cheeks, brows, and heads.

Body armor was worn under a soldier’s purple and scarlet colored cloak or a tunic. The armor was usually made up of chain mail or metal plates wired together and attached to leather or fabric. Roman armor covered the torso. Roman plate armor was flexible, but heavy because the armor was made of metal.

Roman shields were large, curved, and were either rectangular or oval shaped, depending on the era. Their shields were made of wood and edged with metal, with a central metal boss.

The Roman Legion

The Roman army was based around the legion, which consisted of approximately 5,000 to 6,000 men. The legions were divided into 10 cohorts of about 500 to 600 men. Each cohort was made up of a century, which equaled 100 men. The Roman centuries were led by Roman centurions, an elite class of experienced fighting officers that formed the backbone of the Roman army.

When the Romans went to battle, they placed the newer recruits in the front lines, with more experience troops place in the second and third lines behind the young recruits. Roman patterns of attack usually involved legionnaires charging up toward the enemy lines, throwing their javelins, before closing in to fight with their shields and short swords.

Roman cavalry units were employed to attack the enemy’s flanks and to pursue fleeing warriors after a defeat by the Romans. Although Roman cavalry units were a small part of the Roman legion, about 300 cavalry men per legion, it was necessary for success on the battlefield.

In 202 B.C, at the battle of Zama in northern Africa, Roman commander Publius Cornelius Scipio defeated Hannibal Barca of Carthage with cavalry. The battle hung in the balance until the Roman cavalry overcame and chased away the Carthaginian cavalry. Later, the Roman cavalry turned around and attacked Hannibal’s infantry from the rear causing the Carthaginians defeat.

The Roman Legion’s Legacy

A few historians argued that the real question is not why Rome fell but why Rome endured so long. The Roman legions made Rome the greatest military power of antiquity. It was an empire built on warfare, violence, brutality, and conquest, but its celebrated legions could not maintain its domination of the Mediterranean world forever. The Roman legions laid the foundation for building western military strategy, tactics, doctrines, and combat operations. The Roman armies exerted a tremendous influence on subsequent European generations. The Roman legions supplied the blueprint for transmitting the Greco-Roman military culture to the celebrated European powers of western civilization.


  1. Nelson, Eric; The Roman Empire; Alpha Books Publications, 2002.
  2. Roberts, Andrew and others; The Art of War; Quercus Publication, 2009.