The legacy of the Middleham Nevilles instead became the object of dispute between King Edward's brothers: Richard, Duke of Gloucester, and Clarence, who had returned to the family fold before the Battle of Barnet. Clarence, whose claim was founded on his marriage to Isabel Neville, gained the earldoms of Warwick and Salisbury. Gloucester acquired the old Neville estates in the north, establishing his claim by marrying Anne Neville, who had been widowed by Prince Edward's death in the final Lancastrian defeat at the Battle of Tewkesbury in 1471. The northern lands and clientage inherited from the Nevilles became Gloucester's main powerbase, and he adopted Middleham Castle as his principal residence until his usurpation of the throne as Richard III in 1483.