William FitzOsbern, 1st Earl of Hereford (1020-22 February 1071) was a cousin of William the Conqueror and one of the great magnates of Norman England during the late 11th century.
Biography[]
William FitzOsbern was the son of Osbern the Steward, the maternal grand-nephew (through marriage) of Duke Richard I of Normandy. His father became one of the young William the Conqueror's guardians after Robert I of Normandy left Normandy to his young son, and FitzOsbern was raised at William's court. He was one of the most staunch supporters of a prospective Norman conquest of England, meeting with the other Norman barons at Lillebonne and convincing them of the feasibility of an invasion of England. Following William's rise to power, he granted the Isle of Wight to FitzOsbern, and, by 22 February 1067, he had been created Duke of Hereford and granted the earldoms of Gloucester, Worcester, and Oxford; the latter titles were meant to serve as incentives for him to conquer those parts of England, which had yet to be subdued. In 1068, he accompanied King William in the subjugation of South West England, and, in March 1069, he was sent to oversee the peace in York. He also played a major part in the suppression of Eadric the Wild's rebellion, and he and his followers proceeded to conquer the Welsh kingdom of Gwent. He went on to build Carisbrooke Castle on the Isle of Wight, Chepstow Castle in South Wales, Wigmore and Clifford Castles in Hertfordshire, Berkeley Castle in Gloucestershire, and Monmouth Castle in Monmouth, Monmouthshire. In 1070, following Baldwin VI of Flanders' death, FitzOsbern agreed to marry Richilde of Hainaut with the hope of inheriting the County of Flanders, only to be slain in battle with Count Robert I of Flanders at the Battle of Cassel on 22 February 1071.