John, King of England Normandy and Anjou until 1259, but John's continental losses and the consequent growth of Capetian power in the 13th century proved to mark a "turning point in European history". John's first wife, Isabel, Countess of Gloucester, was released from imprisonment in 1214; she remarried twice, and died in 1217. John's second wife, Isabella of Angoulême, left England for Angoulême soon after the king's death; she became a powerful regional leader, but largely abandoned the children she had had by John. John had five legitimate children, all by Isabella. His eldest son, Henry III, ruled as King of England for the
Isabella of Castile, Duchess of York elder sister, Constance (d. 1394), who after the death of their father in 1369 claimed the throne of Castile. Isabella accompanied her sister to England, and on 11 July 1372, at about the age of 17, married John of Gaunt's younger brother, Edmund of Langley, 1st Duke of York, fifth son of King Edward III and Philippa of Hainault, at Wallingford, Oxfordshire, as part of a dynastic alliance in furtherance of the Plantagenet claim to the crown of Castile. According to Pugh, Isabella and Edmund of Langley were 'an ill-matched pair'. As a result of her indiscretions, including an affair