The line of the Beauchamp Earls ended in 1449 when Anne de Beauchamp, 15th Countess of Warwick, died. Richard Neville, the "Kingmaker", became the next Earl of Warwick through his wife's inheritance of the title. During the summer of 1469, Neville rebelled against King Edward IV of England and imprisoned him in Warwick Castle. Neville attempted to rule in the King's name; however, constant protests by the King's supporters forced the Earl to release the King. Neville was subsequently killed in the Battle of Barnet, fighting against the King in 1471 during the Wars of the Roses. Warwick Castle then passed from Neville to his son-in-law, George Plantagenet, 1st Duke of Clarence (brother of King Edward IV). George Plantagenet was executed in 1478, and his lands passed onto his son, Edward Plantagenet, 17th Earl of Warwick; however, Edward Plantagenet was only two when his father died, so his lands were taken in the custody of The Crown. He was placed under attainder, and so could not inherit the throne, by King Henry VII of England, being held by the King for fourteen years in the Tower of London until he was executed for high treason in 1499, supposedly for conspiring to escape with the 'pretender' Perkin Warbeck. Edward was the last Earl of Warwick of the title's first creation.