In the Domesday book of 1086 the Island's name is "Wit". William the Conqueror gave its manorial rights to his kinsman William FitzOsbern, who became Lord of the Isle of Wight. Carisbrooke Priory and the fort of Carisbrooke Castle were founded (probably the site had previously been fortified, originally by Romans and subsequently by Jutes or Saxons; there are remains of a late Saxon wall or "burgh" as defence against Viking raiders). Thereafter allegiance on the island was sworn to FitzOsbern as 'Lord' rather than the king, a role subsequently granted to the de Redvers family by Henry I after his succession in 1100.