Earl of Cornwall, Count of Mortain. He received the county of Mortain from his half-brother, William, then duke of Normandy, in about 1048. His work in the region was of critical importance in creating harmony between western Normandy and their eastern neighbors, and between the Normans and the Bretons. His diplomacy was a model for Henry I. He accompanied William in the invasion of England, where he was in command of the chivalry of the Cotentin at the battle of Hastings. His share of the spoil was one of the greatest, as, with the exception of the lands of the King and the church, he received nearly the whole of Cornwall. He is therefore usually considered to be earl of Cornwall but he was known only as count of Mortain. At the time of Domesday, he possessed 797 manors in various counties. In 1069, he, with Robert, count of Eu, defeated the Danes with great slaughter. He joined his brother, the earl of Kent, in rebellion against William Rufus in favor of Robert Curthose, but was subsequently pardoned.