Roman Centurion

The tactical unit within the Roman legion was called "manipulus" which consisted of 60-120 men depending on whether it was a manipulus of the Hastati, Principes or Triarii . Each manipulus contained two centuria each of which was led by a Centurio (Centurion). Out of the two Centurions one was chosen to lead the manipulus and the other would act as backup (Centurio Posterior). Given there were 30 manipuli in a legion (10 for each of the three major classes of infantry) we can say there were 60 centurions in a legion. Each Centurion was supported by an "Optio" who brought up the back of the century/manipulus, a standard bearer called "signifier" and a horn player who sounded tactical orders called "cornicen". A "tesserarius" was in charge of running the guard duty and managing the daily password.

Centurions could either be nominated by the soldiers themselves or by the 6 military tribunes who ran the legion’s operations. They were not necessarily the best fighters but certainly men able to command and lead their men into battle: Being professional soldiers they could build up considerable experience and the best amongst them "Primipili" would be invited to attend (but not contribute) to the war councils held by the legion’s higher ranks (consuls and tribunes).