The cavalry were part of the Auxilia but Roman citizens could also join. Service was for a period of 25 years. A cavalry troop of 32 men was known as a Turma and was commanded by a Decurion. These were then formed into units with 16 or 24 Turmae known as Ala Quingenaria and Ala Milaria. They would be paid more than other Auxilia.
On parade the cavalry would wear elaborate equipment including face masks. The harness and tack were designed to impress with many medallions and ornamentation
Equipment included a mail shirt, helmet designed to provide all round protection, a flat oval shield, a sword called the spatha that was longer than the legionary gladius, stabbing spears and darts
The elite cavalry fought in Alae which means ‘wings’ in Latin. Typically they would fight on the flanks of the infantry. If the enemy was defeated they would chase and ride down the fleeing enemy.
There were also Cohortes with a cavalry contingent attached known as Cohortes Equitatae. These mixed units tended to be of a lower quality than the Alae
The cavalry had no stirrups, but the saddle had four horns and kept the rider securely in place.