In Augustean time, a legion consisted of ten cohorts. One cohort – »cohors« in Latin – counted three maniples consisting of two centuries (»centuria« in Latin), which were each commanded by a centurion. 80 soldiers, who were distributed into groups of eight persons who shared a tent, constituted a century. The ten groups of soldiers sharing a tent were called »contubernia.« Each contubernium possessed a leather tent (»tabernaculum«), a handmill made of basalt used to grind grain to flour, the main ingredient of »puls«, the Roman equivalent of porridge, as well as a mule for transportation plus a muleteer (»mulio«), who did not belong to the fighting unit.
The cohort was commanded by the »pilus prior«, the highest-ranking centurion. Apart from centurions, other officers and personnel also belonged to a cohort, which therefore counted 480 heavily armed foot soldiers as well as 120 further persons, that is, a total of 600.