 This class is often translated as "knight"; the medieval knight, however, was called "miles" in Latin (which in classical Latin meant "soldier", normally infantry).In the later Roman Empire, the classical Latin word for horse, "equus", was replaced in common parlance by the vulgar Latin "caballus", sometimes thought to derive from Gaulish "caballos".From "caballus" arose terms in the various Romance languages cognate with the (French-derived) English "cavalier"