Hekatontarch

A centurion (Latin: centurio; Greek: κεντυρίων, kentyríōn, or ἑκατόνταρχος, hekatóntarkhos) was a professional officer of the Roman army after the Marian reforms of 107 BC. Most centurions commanded groups of centuries of around 80 men but senior centurions commanded cohorts or took senior staff roles in their legion. Centurions were also found in the Roman navy. In the Byzantine Army, they are also known by the name kentarch (κένταρχος, kentarchos). Their symbol of office was the vine staff, with which they disciplined even Roman citizens protected from other forms of beating by the Porcian Laws.

In the Roman infantry, centurions initially commanded a centuria or "century". Centuries, or centuriae, developed from the Roman tribal system under the Servian reforms and could contain 200 to 1000 men. Later, generals and Caesars further manipulated these numbers with double and half-strength units. Julius Caesar, for instance, made the first century double strength.

Centurions seemed to receive a much higher rate of pay than the average legionary, twice as much or more (possibly as much as 17 times as much as a legionary soldier). Veteran legionaries often worked as tenants of their former centurions.

During the Imperial era, centurions gradually rose in seniority in their cohort, commanding centuries with higher precedence, until commanding the senior century and therefore the whole cohort. The very best centurions were then promoted to become centurions in the First Cohort, called Primi Ordines, commanding one of the ten centuries and also taking on a staff role. The most senior centurion of the legion was the Primus Pilus who commanded the first century. All centurions, however senior, had their own allocated century. There was little difference between the ranks of centurions except for the Primus Pilus. The Primus Pilus also participated in war councils.

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