Carisbrooke Castle
Originally a Roman fort, the castle built in the centre of the Isle of Wight was put up soon after William the Conqueror came to England. The Earl of Hereford, William Fitz Osbern may have been responsible for its construction, but he was killed in battle during 1070/1071 and so would have had little opportunity to oversee the construction. Osbern's son, Roger, is more likely to have built or refortified the castle.
It was at Carisbrooke Castle that William arrested his own half brother, Odo for acts of treason. Henry I granted the castle in the first year of his reign to Richard de Redvers. The Redvers family owned the castle for much of the Medieval period, only ending in November 1293 when the last Redvers, Isabel died. In 1136, Baldwin de Redvers took refuge in the castle on the run from King Stephen . Unfortunately the wells on the island ran dry and Baldwin gave up the land in exchange for his head. Baldwin's land was restored to him in 1153 when Henry II became king. Baldwin, the last male in the line, died in 1216 poisoned, it is said by Peter of Savoy. Isabela de Fortibus, Baldwin's sister took control of the castle and successfully ran it until her death in 1293.

http://www.patpnyc.com/exeter.htm
Baldwin de Redvers, son of a father of the same name, by his wife Margaret Fitz-Gerald of Harewood, succeeded William de Vernon, his grandfather, as seventh earl. He married Amicia, daughter of Gilbert, Earl of Gloster, and died in 1245.