Organization of the Roman Military 150 CE
It was the strength and proficiency of the Roman army that held the empire together against internal revolts and threats from beyond the borders. The army was unique in the classical world: a professional standing army, with state-provided weapons and armor, salaried troops, and 30 or so legions (the main body of the army) permanently stationed at garrison towns along imperial frontiers. Legions were reinforced with auxiliary troops drawn from the local population. To support the army and protect merchant shipping from piracy, Rome maintained a large navy with fleets in the Mediterranean Sea, the Atlantic Ocean, and along the Rhine and Danube Rivers.
LEGION UNITS Legion A body of about 5,000 foot soldiers, uniformly legionaries (160 in first cohort centuries). There were 6 trained and equipped—similar to a modern army division. centuries in the 2nd to 10th cohorts and 5 in the first A legion was the smallest formation in the Roman army cohort. capable of sustained independent operations. Cavalry A small force of about 120 mounted legionaries Cohort (10) The distinct tactical units of a legion, each attached to each legion for escort, messenger, and about 480 men strong—equivalent in size and function to reconnaissance duties. They were not usually seen on a modern infantry battalion. The first cohort was the battlefield. approximately double strength (around 800 men) and Artillery Each legion had 60 engines (catapults). One contained the best soldiers. engine was capable of shooting yard-long, heavy bolts Century (59) An administrative unit within a cohort. A (metal arrows) more than 400 paces (333 yds/305 m). century (equivalent to a modern infantry company) had Used against cities and obstacles rather than on the its own officers, a standard-bearer, a trumpeter, and 80 battlefield.
A LEGION IN BATTLE FORMATION enemy
Cohort 4 Cohort 3 Cohort 2 Cohort 1 Century of 1st cohort Century of 2nd Cohort 7 Cohort 6 Cohort 5 to 10th cohorts
Officers Cohort 10 Cohort 9 Cohort 8
LEGION PERSONNEL COMMAND STRUCTURE OFFICERS Legatus Overall commander of the legion and usually a senator. A political appointee of the emperor for a limited period, usually two years. Loyalty to the emperor was more important than military proficiency. LEGATUS Tribunus laticlavius Senior staff officer, usually an aristocrat who served a short term before entering the Senate (government advisory council). TRIBUNUS LATICLAVIUS Tribuni angusticlavii (5) Junior staff officers, usually from wealthy backgrounds. Praefectus castrorum Prefect of the camp. An TRIBUNI PRAEFECTUS experienced ex-centurion responsible for the discipline ANGUSTICLAVII CASTRORUM of the legion and the organization and maintenance of its encampment or base. PRIMUS PILUS OTHER PERSONNEL Primus pilus Senior centurion, usually given this post after 18 years’ service. Nominally in charge of the first AQUILIFER cohort and century. Aquilifer Legion’s eagle standard-bearer. Centurion (59) Experienced soldiers promoted to lead CENTURIONS a century. Signifer Century’s standard-bearer. SIGNIFER Legionaries Soldiers of the legion.
LEGIONARIES