1911 Encyclopædia Britannica/Centurion

CENTURION (Lat. centurio), in the ancient Roman army, an officer in command of a centuria, originally a body of a hundred infantry, later the sixtieth part of the normal legion. There were therefore in the legion sixty centurions, who, though theoretically subordinate to the six military tribunes, were the actual working officers of the legion. For the most part the centurions were promoted from the ranks: they were arranged in a complicated order of seniority; the senior centurion of the legion (primus pilus) was an officer of very high importance. Besides commanding the centuries of the legion, centurions were “seconded” for various kinds of special service, e.g. for staff employment, the command of auxiliaries. See further Roman Army.