Fitzosbern, William, earl of Hereford (d. 1071). Fitzosbern, steward at the court of Normandy, was one of William the Conqueror's most trusted advisers and fought at Hastings. In reward he was given great estates in the west country, the rank of earl, and palatine powers. Much of his energy went into fighting the Welsh and establishing the Norman position in Glamorgan.