Cohort (military unit)

: cohortes; see wikt:cohors for full inflection table) was a standard tactical military unit of a Roman legion.

Pilus was a name for a maniple of triarii, reflecting their use as spearmen, pilum being the Latin word for a javelin.

They tended to the pack mule, ensured legionaries had water on the march, and camp duties such as cooking, washing, and other specialised skills such as smithing or carpentry.

[7] The centurion was assisted by an optio, who served as his second-in-command, and typically received double the legionary rate of pay.

Third in seniority was a tesserarius, who exercised command over the nightly guard duties, and were responsible for distributing the watchwords for the camp.

Thus, a cohort would consist of, on paper, 480 legionaries, 6 centurions, and 24 junior officers, with logistical support provided by 60-120 slaves, and 60-120 mules.

It was the unique honour of the first cohort's aquilifer to carry the legion's aquila, or eagle, standard into battle, which possessed a quasi-religious importance to the legionaries.

A legion's first cohort also had an imaginifer, who carried an imago of the reigning Emperor, typically a three-dimensional relief of their likeness made of beaten metal.

According to Vegetius, a 4th-century Roman author, each century was equipped with a scorpio, a small torsion-powered ballista, for a total of six per cohort.