The Knight is a mounted unit in Civilization Revolution.
Like most other combat units, the Knight can attack and defend against enemies. Whether fighting other civilizations or just some feeble barbarians, the Knights are powerful, highly mobile units. The trusty steeds they are mounted on really give them that extra punch in battle. Their only weakness is their defense, which is relatively poor. Three units can be combined to create an army of Knights, which is the most powerful mobile attack force in the Medieval Era.
Japanese Knights are replaced by the Samurai Knight.
Roman Knights are replaced by the Cataphract, which in history was a heavily armoured Roman cavalry unit. Compared to the regular Knight, it has a slightly higher attack.
Spanish Knights are replaced by the Conquistador, a Spanish conqueror.