Rider (ライダー, Raidā) is the Rider-class Servant of Waver Velvet in the Fourth Holy Grail War of Fate/Zero. Rider's True Name is Alexander the Great (アレキサンダー大王, Arekisandā-daiō), the King of Conquerors (征服王, Seifuku-Ō), summoned as the adult aspect known by the name Iskandar (イスカンダル, Isukandaru) rather than the youthful aspect known as Alexander (アレキサンダ, Arekisanda). Known by many names, Alexander, Iskandar, and Alexandros, he was the young prince of the small kingdom of Macedonia in the 4th Century BC, said to have been the son of Zeus in many stories despite absence of clear evidence.