A military tribune (from Latin tribunus militum 'tribune of the soldiers') was an officer of the Roman army who ranked below the legate and above the centurion.
[5] Additionally, in the early Republic, another type of military tribune was sometimes chosen in place of the annually elected consuls to be the heads of the Roman State.
The reasons for this choice are obscure, though Livy often cast the decision according to the class struggles he saw as endemic during this period, with patricians generally favoring consuls and plebs the military tribunes.
The second-in-command to the legate was the tribunus laticlavius or 'broad-stripe' tribune (named after the width of the stripe used to demarcate him on his tunic and toga),[6] usually a young man of senatorial rank.
These 'officer cadets'[6] were men of equestrian rank who had military experience, and yet had no authority: they were allowed to sit on a court martial but they held no power in battle.
[8] Under Augustus, the five equestrian tribunes were sometimes promoted from the rank of centurion, and might advance to a command in the auxiliary cavalry or Praetorian Guard.