 In the reign of Æthelstan (924–939) Wigred, thought by Simon Keynes to have been Bishop of Chester-le-Street, attested royal charters.According to George Molyneaux, the church of St Cuthbert "was in all probability the greatest landholder between the Tees and the Tyne".Traditionally, following the chronology of the twelfth-century writer Symeon of Durham, historians have believed that the body of St Cuthbert and centre of the diocese lay at Chester-le-Street from the ninth century until 995, but recent research has suggested that the bishops may have been based at Norham on the River Tweed until after 1013.