Helmets of Roman auxilia cavalry

Prior to the Republican period, Rome depended on their non-citizen allies to provide, train, and equip cavalry known as the Foederati. But, when the Republic transitioned into the Empire, Augustus created a regular Auxilia corps. Although still non-citizens, these troops were now a regular part of the Roman army that were paid and trained by the Roman State. A typical cavalryman of an ala would be paid 20 percent more than a typical citizen legionary. Roman auxilia cavalry were usually heavily armored in mail and armed with a short lance, javelins, the spatha long sword, and sometimes bows for specialist horse archer units. These men primarily served as medium missile cavalry for flanking, scouting, skirmish, and pursuit. Riders and horses were housed together in the same barracks. Structurally, a cavalry alae of the type ala quingenaria consisted of 480 horseman (ideally) divided into 16 turnmae of 30 men each under a decurio. The ala milliaria, however, contained 1008 hors...