John, King of England treatment of many of England's most powerful nobles. Although both John and the barons agreed to the " peace treaty in 1215, neither side complied with its conditions. Civil war broke out shortly afterwards, with the barons aided by Louis of France. It soon descended into a stalemate. John died of dysentery contracted whilst on campaign in eastern England during late 1216; supporters of his son Henry III went on to achieve victory over Louis and the rebel barons the following year. Contemporary chroniclers were mostly critical of John's performance as king, and his reign has since been the subject
Isabella of Castile, Duchess of York Isabella of Castile, Duchess of York Isabella of Castile, Duchess of York (1355 – 23 December 1392) was the daughter of King Peter and his mistress María de Padilla (d. 1361). She accompanied her elder sister, Constance, to England after Constance's marriage to John of Gaunt, 1st Duke of Lancaster, and married Gaunt's younger brother, Edmund of Langley, 1st Duke of York. Isabella was the youngest of the three daughters of King Peter of Castile by his favourite mistress, María de Padilla (d.1361). On 21 September 1371 Edward III's fourth son, John of Gaunt, 1st Duke of Lancaster, married Isabella's