Stables provide three horses each. When built, it starts with no horses and it slowly fills up its stocks. Knights and the lord can optionally mount horses by clicking a button, which causes a horse to come out from the stable and run to the mounting unit.
This also works backwards, as after the rider dismounts, the horse will move back into its place. Disbanded horses will retain their current health until remounted.
Horse riders can greatly enhance their movement speed and health when mounting horses.