Primus pilus

"first maniple of triarii"[1]) or primipilus was the senior centurion of the first cohort in a Roman legion,[2][3] a formation of five double-strength centuries of 160 men each;[4] he was a career soldier and advisor to the legate.

[4][5] During the Roman Empire, the emperor Claudius created the office of primus pilus iterum.

To become the primus pilus iterum an officer must have formerly served as a tribune in the vigiles, cohortes urbanae, or Praetorian Guard.

The primus pilus iterum would hold the responsibility of a praefectus castrorum but with higher pay.

[4][clarification needed] Only eight officers in a fully officered legion outranked the primus pilus: The legate (legatus legionis), commanding the legion; the senior tribune (tribunus laticlavius); the camp prefect (praefectus castrorum); and the five junior tribunes (tribuni angusticlavii).