William of Hauteville, called Iron Arm, count of Melfi

The son of Tancred de Hauteville, William, together with his brothers Drogo and Humphrey, around 1035 fought as a mercenary for Guaimar V of Salerno. In 1042, after he had conquered numerous Byzantine territories west of the River Ofanto, Guaimar made him count of Melfi. After his death in 1046 he was succeeded by his brother Drogo.