The Earl of Warwick had been at odds with Edward IV for some time, resenting the rise in the king's favour of the new queen's family, the Woodvilles. In 1469, the earl tried to put his son-in-law George on the throne, but met resistance from Parliament. After a second rebellion against King Edward failed in early 1470, he was forced to flee to France, where he allied himself with the ousted House of Lancaster in 1470. With King Henry VI imprisoned in the Tower of London, the "de facto" Lancastrian leader was his consort, Margaret of Anjou, who was suspicious of Warwick's motives. To quell these suspicions, Anne Neville was formally betrothed to the son of Henry VI and Margaret of Anjou, Edward of Westminster, at the Château d'Amboise in France. They were married in Angers Cathedral, probably on 13 December 1470, to make Anne Neville the Princess of Wales.