Roman cavalry (Latin: equites Romani) refers to the horse-mounted forces of the Roman army throughout the regal, republican, and imperial eras.
In the regal era, the Roman cavalry was a group of 300 soldiers called celeres, tasked with guarding the Kings of Rome. Later their numbers were doubled to 600, then possibly 1,800. All of the cavalrymen were patricians. In the republican era, the general name for the cavalry was equites and these united consisted of the equestrian class and the first class, with a group of 300 cavalrymen in every legion. They were divided into 10 groups of 30 men. Each group elected three leaders known as decuriones. Later the Roman cavalry stopped using Roman citizens as cavalrymen and relied on Auxilia and foreign recruits.
Roman cavalrymen wore a Corinthian helmet, bronze chestplate, and bronze greaves. Later mail was adopted into the army. Their arms included a lance (lancea), a long sword (spatha), and a short throwing spear.
Historians such as Philip Sidnell argue that the Roman cavalry was a crucial part of the republican army. However, other historians bring up defeats such as Cannae and Trebia as evidence against this claim. Cavalry tactics included fighting the enemy cavalry first, then attacking the enemy army from multiple directions to distract the commander and break their defensive line. In the Late Empire light cavalry and mounted archers were used for skirmishing.