Lady Isabel Neville (5 September 1451 – 22 December 1476) was the elder daughter and co-heiress of Richard Neville, 16th Earl of Warwick (the Kingmaker of the Wars of the Roses), and Anne de Beauchamp, suo jure 16th Countess of Warwick. She was the wife of George Plantagenet, 1st Duke of Clarence. She was also the elder sister of Anne Neville, who was Princess of Wales by her first marriage and Queen consort of England by her second. Life Isabel Neville was born at Warwick Castle, the seat of the Earls of Warwick, on 5 September 1451. On 11 July 1469, Isabel secretly married George Plantagenet, 1st Duke of Clarence, the younger brother of Edward IV in Calais. The marriage was arranged against the King's wishes by her father, and the ceremony was conducted by Isabel's uncle George Neville, archbishop of York. Following their marriage, Clarence joined forces with Warwick and allied with the Lancastrians led by Margaret of Anjou, queen consort to Henry VI. After Isabel Neville's sister Anne was married to Edward of Westminster, Prince of Wales, the son and heir of Henry VI, Clarence rejoined his brother, realizing that it was now unlikely that he would become king. Letters, from King Edward, were taken to Clarence by an unnamed lady who came to visit Isabel before Warwick and Clarence invaded England for the Lancastrians in September 1470. Inside these letters were promises of reconciliation from the king if Clarence abandoned the cause of Warwick and the Lancastrians. Clarence replied that he would join King Edward as soon as was conveniently possible. Marriage and children Isabel Neville married George Plantagenet, 1st Duke of Clarence, in Calais, France, on 11 July 1469. Four children resulted: No name (c. 17 April 1470), born outside Calais. Died at sea. Identified by some sources as a girl named Anne, and by others as an unnamed boy. Margaret Pole, 8th Countess of Salisbury (14 August 1473 – 27 May 1541). Married Sir Richard Pole; executed by Henry VIII. Edward Plantagenet, 17th Earl of Warwick (25 February 1475 – 28 November 1499). Executed by Henry VII for attempting to escape from the Tower of London. Richard of Clarence (6 October 1476 – 1 January 1477), born at Tewkesbury Abbey, Gloucestershire, died at Warwick Castle, Warwickshire, buried Warwick. Death Isabel Neville died on 22 December 1476, two and a half months after the birth of