In 1447 the Manor was granted in dower to the Duke of Warwick's widow, Cecily, who died in 1450, her daughter Anne Countess of Warwick having preceased her. The Manor reverted to Richard Nevill and his wife Anne (sister of Henry Duke of Warwick), who shortly before had been created Earl and Countess of Warwick. They made a settlement concerning part of it in 1466. He, usually known as the “King Maker”, was slain at the battle of Barnet in 1471, when his widow's rights in the Manor were ignored in favour of Richard Duke of Gloucester, huband of their daughter Anne. In 1488 Anne Countess of Warwick, having recovered her rights surrendered the Manor, with other Warwick estates to the Crown. From this time it is sometimes called Hanslope alias Castlethorpe Manor.