John of Gaunt III's rule was becoming unpopular due to high taxation and his affair with Alice Perrers, political opinion closely associated the Duke of Lancaster with the failing government of the 1370s. Furthermore, while King Edward and the Prince of Wales were popular heroes due to their successes on the battlefield, John of Gaunt had not won equivalent military renown that could have bolstered his reputation. Although he fought in the Battle of Nájera (1367), for example, his later military projects proved unsuccessful. When Edward III died in 1377 and John's ten-year-old nephew succeeded as Richard II of England, John's influence strengthened.
Edward II of England the Count of Flanders, but this too failed after it was blocked by King Philip IV of France. Between 1297 and 1298, Edward was left as regent in charge of England while the king campaigned in Flanders against Philip IV, who had occupied part of the English king's lands in Gascony. On his return, Edward I signed a peace treaty, under which he took Philip's sister, Margaret, as his wife and agreed that Prince Edward would in due course marry Philip's daughter, Isabella, who was then only two years old. In theory, this marriage would mean that the disputed Duchy