The Percies added a new great hall to the castle shortly after they took possession of it. Henry Percy, 1st Earl of Northumberland fought against Henry IV and took part in the Battle of Shrewsbury, for which act he was attainted and his estates, including Prudhoe, were forfeited to the Crown in 1405. That same year it was granted to the future Duke of Bedford, (a son of Henry IV) and stayed in his hands until his death in 1435, whereupon it reverted to the Crown.