In the republic alae sociōrum were two bodies of Roman allies, including cavalry and infantry, each equivalent in size to a legion, which fought on the wings of the battle‐line. After the Social War the Romans increasingly recruited cavalry from native peoples, and Caesar used Gallic and German cavalry units to great effect, usually placing them under their own commanders. During the Civil War some native contingents were used by the military dynasts under the command of Roman officers or veteran soldiers. In Augustus' reorganization of the army, many non‐Roman infantry and cavalry units were incorporated into the formal structure of the army as auxilia. Alae (now used exclusively of cavalry) normally consisted of about 480–500 men divided into sixteen troops. Alae were commanded by equestrian prefects, who in the three posts often held by equestrian officers ranked above the prefects of auxiliary infantry cohorts and military tribunes. Cavalrymen of the alae probably received 1,050 sesterces a year under Augustus, equivalent to the pay of a legionary cavalryman and more than that of a legionary infantryman (see stipendium). Alae were originally enlisted from ethnic groups, and although this racial character was later diluted by wider recruiting including the admission of some citizens, they often retained their regional titles (e.g. ‘first ala of Spanish’); a few bore personal names indicating the officer who had first raised or commanded them (e.g. ‘ala Agrippiana’); many were named after an emperor as a mark of honour or because he had recruited them; and some titles indicated methods of fighting.
Subjects: Classical Studies.