Cohort – Backbone of the Roman Legion
Cohort was a standard unit in the Roman army which divided the legion into 10 parts. Number of soldiers in this tactical unit varied through history, until the Gaius Marius (157 BC–86 BC) reforms took place. His reforms replaced the old manipular system and introduced a modern cohort. These new standards made cohort into a moder unit consisted of 480 personnel, broken down into six centuriae (80 men each). Tribunus cohortis commanded the unit– it was usually the most senior Centurion from one of the centuriae from the unit.
1 Legion = 10 Cohorts /1 Cohort = 6 centuriae / 1 Centuria = 10 Contubernia / 1 Contubernia = 8 Soldiers
The first cohort of the legion was almost double the size of a regular one. It was made up of five double-strength centuries totaling 800 fighting men. First century in this unit had the best soldiers in the legion led by the most experienced Centurion – the primus pilus (first file or first spear).
Strength of the cohort
The strength of a Roman cohort comes from it’s arrangement – experienced, inexperienced, most and least elite soldiers were mixed thought the formations that gave each cohort a great boost of morale. Cohort was given a name according to it’s structure and experience
Names and types:
- Cohors peditata – infantry cohort (legionnaires)
- Cohors alaria – auxiliary unit consisted of non-Roman citizens
- Cohors sagittaria – unit consisted of bowmen and archers
- Cohors equitata – auxiliary unit with mounted squadrons
- Cohors speculatorum – scouts
- Cohors classica – sailors and marines
- Cohors tumultuaria – cohort of irregular auxiliary troops (also known as “chaos” cohort)
Each cohort was given it’s number (from 1-10) although there was no particular order of numbering. The only exception was the first cohort, which was always the most elite one.
There were also cohorts that were not in the legion’s structure, most famous being cohortes praetoriae. The (in)famous Prehistorians were bodyguards of generals and emperors. Ironically they were often the ones who murdered the ones they meant protecting.