The historian David Hey describes Conisbrough as appearing to be the most important place in Anglo-Saxon and Viking South Yorkshire. In a will of around 1003, Conisbrough was bequeathed by Wulfric Spott, founder of Burton Abbey. At this point, it appears to have been the centre of a major former royal estate, reaching Hatfield Chase. The manor became royal again under Harold II of England, and by the Norman Conquest, 28 townships in what is now South Yorkshire belonged to the Lord of Conisbrough. William the Conqueror gave the whole lordship to William de Warenne.