Land of Legends
Cavalry can be thought of as The Horseman combined with The Lancer. The wield heavy polearms with one hand, a shield in the other, and are adept at charging on horseback into the enemy ranks. Unlike the Lancer however, their goal is not to be the bulwark of a fighting force, but instead to smash through the defenses of the enemy crushing everything under their feet.
Cavalry are expensive and so their numbers are considered fairly limited. Heavy stout animals that have the bulk, speed, and endurance for them to ride combined with the ability to carry the bulk of the cavalry trooper and his gear is hard to find. The gear, and their penchant for breaking it, also leads to them being expensive.