until the 11th century. Organization Crews The bulk of a galley's crew was formed by the rowers, the (sing. ) or (sing. ) in Greek. Despite popular perceptions, the Roman fleet, and ancient fleets in general, relied throughout their existence on rowers of free status, and not on galley slaves. Slaves were employed only in times of pressing manpower demands or extreme emergency, and even then, they were freed first. In Imperial times, non-citizen freeborn provincials (peregrini), chiefly from nations with a maritime background such as Greeks, Phoenicians, Syrians and Egyptians, formed the bulk of the fleets' crews.Starr (1960), p. 75 Table 1 During the early Principate, a ship's crew, regardless of its size, was organized as a centuria. Crewmen could sign on as marines (Called Marinus), rowers/seamen, craftsmen and various other jobs, though all personnel serving in the imperial fleet were classed as milites ("soldiers"), regardless of their function; only when differentiation with the army was required, were the adjectives classiarius or classicus added. Along with several other instances of prevalence of army terminology, this testifies to the lower social status of naval personnel, considered inferior to the auxiliaries and the legionaries. Emperor Claudius first gave legal privileges to the navy's crewmen, enabling them to receive Roman citizenship after their period of service. This period was initially set at a minimum of 26 years (one year more than the legions), and was later expanded to 28. Upon honorable discharge (honesta missio), the sailors received a sizable cash payment as well. As in the army, the ship's centuria was headed by a centurion with an optio as his deputy, while a beneficiarius supervised a small administrative staff. Among the crew were also a number of principales (junior officers) and immunes (specialists exempt from certain duties). Some of these positions, mostly administrative, were identical to those of the army auxiliaries, while some (mostly of Greek provenance) were peculiar to the fleet. An inscription from the island of Cos, dated to the First Mithridatic War, provides us with a list of a ship's officers, the nautae: the gubernator (kybernētēs in Greek) was the helmsman or pilot, the ( in Greek) supervised the rowers, a proreta (prōreus in Greek) was the look-out stationed at the bow, a pentacontarchos was apparently a junior officer, and an iatros (Lat. medicus), the ship's doctor. Each ship was commanded by a trierarchus, whose exact relationship with the