survived into adulthood, creating a large pool of competitors for offices and estates, as well as in the matrimony market. Resentment built when her sisters made a series of advantageous unions, including that of Catherine Woodville to Henry Stafford, 2nd Duke of Buckingham; Anne Woodville to William, heir to Henry Bourchier, 1st Earl of Essex; and Eleanor Woodville with Anthony, heir to Edmund Grey, 1st Earl of Kent. In 1467, Edward dismissed his Lord Chancellor, Warwick's brother George Neville, Archbishop of York. Warwick responded by building an alliance with Edward's disaffected younger brother and heir, the Duke of Clarence, who held estates adjacent to the Neville heartland in the north. Concerned by this, Edward blocked a proposed marriage between Clarence and Warwick's eldest daughter Isabel. In early July, Clarence defied his brother by traveling to Calais, where he married Isabel in a ceremony conducted by George Neville and overseen by Warwick. The three men issued a 'remonstrance', listing alleged abuses by the Woodvilles and other advisors close to Edward and then returned to London, where they assembled an army to remove these 'evil councillors' and establish good government. With Edward still in the north, the royal army was defeated by a Neville force at Edgecote Moor on 24 July 1469. After the battle, Edward was held in Middleham Castle; on 12 August, his father-in-law Richard Woodville and Richard's younger son, John Woodville, were executed at Kenilworth. However, it soon became clear there was little support for Warwick or Clarence; Edward was released in September and resumed the throne. Outwardly, the situation remained unchanged, but tensions persisted and Edward did nothing to reduce the Nevilles' sense of vulnerability. The Percys, traditional rivals of the Neville family in the North, fought for Lancaster at Towton; their titles and estates were confiscated and given to Warwick's brother John Neville. In early 1470, Edward reinstated Henry Percy as Earl of Northumberland; John was compensated with the title Marquess of Montagu, but this was a significant demotion for a key supporter. In March 1470, Warwick and Clarence exploited a private feud to initiate a full-scale revolt; when it was defeated, the two fled to France in May 1470. Seeing an opportunity, Louis XI persuaded Warwick to negotiate with his long-time enemy, Margaret of Anjou; she eventually agreed, first making him kneel before her in silence for fifteen minutes. With French support, Warwick landed in England