Duke of Aquitaine House of Valois claimed supremacy over Aquitaine. In 1360, both sides signed the Treaty of Bretigny, in which Edward renounced the French crown but remained sovereign Lord of Aquitaine (rather than merely duke). However, when the treaty was broken in 1369, both these English claims and the war resumed. In 1362, King Edward III, as Lord of Aquitaine, made his eldest son Edward, Prince of Wales, Prince of Aquitaine. In 1390, King Richard II, son of Edward the Black Prince appointed his uncle John of Gaunt Duke of Aquitaine. This grant expired upon the Duke's death, and the dukedom reverted
Edward the Black Prince In order to attach John, Duke of Brabant, to his cause, the king in 1339 proposed a marriage between the young Duke of Cornwall and John's daughter Margaret, and in the spring of 1345 wrote urgently to Pope Clement VI for a dispensation for this marriage. On 12 May 1343, Edward created the duke Prince of Wales, in a parliament held at Westminster, investing him with a circlet, gold ring, and silver rod. The prince accompanied his father to Sluys on 3 July 1345, and Edward tried to persuade the burgomasters of Ghent, Bruges, and Ypres to accept his son