Wiki Details
A centurion (; Latin: centurio [kɛn̪ˈt̪ʊrioː], pl. centuriones; Ancient Greek: κεντυρίων, romanized: kentyríōn, or Ancient Greek: ἑκατόνταρχος, romanized: hekatóntarkhos) was a type of officer in the Roman army who commanded a group of soldiers called a centuria or "century".
The term centurion is derived from the Latin word centurio, which itself originates from centum, meaning "hundred." Initially, centurions were commanders of a unit of roughly 100 soldiers, although the exact number varied over time and by period. The concept of the centurion emerged during the early Roman Republic (509–27 BCE), when Rome's military was based on citizen-soldiers organized into centuries (centuriae), units of 100 men within the Roman legion (legio).
Relative to modern military ranks, centurions are variously described as or equated to non-commissioned officers (NCOs), warrant officers, and as commissioned officers. Scholarly consensus holds that the position was a blend of NCO-status and commissioned officer-status, and close to various grades of captain in terms of a direct analogy to modern rank. The Roman ranks of decanus and optio are generally regarded as being closer to classification as NCOs than centurions.
General info from Wikipedia.org