William FitzOsbern, 1st Earl of Hereford

William FitzOsbern, 1st Earl of Hereford, Lord of Breteuil ( 1011 – 22 February 1071), was a relative and close counsellor of William the Conqueror and one of the great magnates of early Norman England. FitzOsbern was created Earl of Hereford in 1067, one of the first titles in the English peerage. He is one of the very few proven companions of William the Conqueror known to have fought at the Battle of Hastings in 1066. His chief residence was Carisbrooke Castle on the Isle of Wight, one of many castles he built in England.

Origins William FitzOsbern was the son of Osbern the Steward, a nephew of Duchess Gunnor, the wife of Duke Richard I of Normandy. Osbern was the steward of his cousin Duke Robert I of Normandy. When Robert left the Duchy to his young son William, Osbern became one of Duke William's guardians. Osbern married Emma, a daughter of Count Rodulf of Ivry, who was a half-brother of Duke Richard I of Normandy. Through her he inherited a large property in central Normandy, including the honours of Pacy and Breteuil.

Career pre-1066 A 17th-century depiction of Lyre Abbey in Normandy, which was founded by FitzOsbern and his wife, Adeliza. William FitzOsbern was probably raised at the court of his cousin William, Duke of Normandy, and like his father, became one of the ducal stewards. (In Normandy, he used the title comes palatii, count of the palace.) Historian C. P. Lewis observed that "Historians writing in the nineteenth century and for much of the twentieth called William a 'palatine earl', an inappropriate translation of the title which he had used in Normandy; there were no palatine earldoms in England until the thirteenth century."

He was one of the earliest and most vigorous advocates of the invasion of England, and tradition holds that, at the Council of Lillebonne, he convinced the doubters amongst the Norman barons of the feasibility of the invasion. FitzOsbern's younger brother Osbern FitzOsbern was one of Edward the Confessor's chaplains, and possessed the rich church of Bosham in Sussex, where King Harold went to in the first scene of the Bayeux Tapestry, and was well placed to pass along intelligence on the situation in England. He later became Bishop of Exeter.

In England after 1066 After William became King of England, FitzOsbern was made an earl, with major land holdings in Gloucestershire, Herefordshire, Oxfordshire, and the Isle of Wight, and smaller areas under his authority in Berkshire, Dorset, Wiltshire, and Worcestershire. Roger de Breteuil, 2nd Earl of Hereford, who succeeded his father in England and Wales; Emma de Breteuil, wife of Ralph de Gael, 1st Earl of Norfolk and William de Vernon. Adela married John, Lord of Croy Secondly, it is assumed he married Richilde, Countess of Mons and Hainaut in 1070, shortly before the Battle of Cassel. They had a son who was taken to the Burgundy region of Savoy. Godfrey de Crepon Candie

Cultural depictions A fictional version of FitzOsbern is portrayed by Ingvar Eggert Sigurðsson in the 2025 TV series King & Conqueror.