The ''primus pilus'' or ''primipilus'' was the senior
centurion
A centurion (; la, centurio , . la, centuriones, label=none; grc-gre, κεντυρίων, kentyríōn, or ) was a position in the Roman army during classical antiquity, nominally the commander of a century (), a military unit of around 80 ...
of the first
cohort
Cohort or cohortes may refer to:
* Cohort (educational group), a group of students working together through the same academic curriculum
* Cohort (floating point), a set of different encodings of the same numerical value
* Cohort (military unit ...
in a
Roman legion
The Roman legion ( la, legiō, ) was the largest military unit of the Roman army, composed of 5,200 infantry and 300 equites (cavalry) in the period of the Roman Republic (509 BC–27 BC) and of 5,600 infantry and 200 auxilia in the period of ...
, a formation of five double-strength centuries of 160 men, was called the ''primus pilus'';
he was a career soldier and advisor to the
legate
Legate may refer to:
*Legatus, a higher ranking general officer of the Roman army drawn from among the senatorial class
:*Legatus Augusti pro praetore, a provincial governor in the Roman Imperial period
*A member of a legation
*A representative, ...
. The ''Primus Pilus'' would remain in command for one year. They could continue to serve in the army after their term ended if there was a vacancy in command or if they wished to become an independent commander of an ''
auxilia
The (, lit. "auxiliaries") were introduced as non-citizen troops attached to the citizen legions by Augustus after his reorganisation of the Imperial Roman army from 30 BC. By the 2nd century, the Auxilia contained the same number of inf ...
'' unit or the ''
praefectus castrorum
The ''praefectus castrorum'' ("camp prefect") was, in the Roman army of the early Empire, the third most senior officer of the Roman legion after the legate (''legatus'') and the senior military tribune (''tribunus laticlavius''), both of whom w ...
''.
During the
Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
, 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
The ''Vigiles'' or more properly the ''Vigiles Urbani'' ("watchmen of the City") or ''Cohortes Vigilum'' ("cohorts of the watchmen") were the firefighters and police of ancient Rome.
History
The ''Triumviri Nocturni'' (meaning ''three men of th ...
'', ''