Underuse of cavalry in the roman army

[Legio Tredecim Gemina]

Underuse is probably an incorrect word. The ancient Roman army was in the main an infantry army, and in the Republic and early Empire the best in the world. Cavalry was used for reconnaissance and to protect flanks of infantry formations. While it was used to give protection on the flanks, its primary role was harassment of the enemy flanks and in pursuing fleeing enemy soldiers. In the early era, Rome did not develop its cavalry for use common to later eras. It was really in the Eastern provinces in which Rome encountered effective, aggressive use of cavalry by Parthians, who used heavily armored cavalry (cataphracts). These were a continual problem for Roman infantry formations. But by the 5th Century, Rome began to develop heavy cavalry for use in the East. In the Eastern (Byzantine) Empire, heavy cavalry became the mainstay of the army. It was easily the equal of, if not superior to, European cavalry.

Warfare is always in a state of flux. If there can be any valid criticism of the Roman army, it is that it did not develop a more effective cavalry. But there is a saying as valid 2,000 years ago as today, generals always plan to fight yesterday's war.