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 with Lancaster, who was then in Brittany. Accordingly he determined to return to Bordeaux by way of Poitiers, and after putting to death most of the garrison of the castle of Vierzon set out on 29 October towards Romorantin. Some French knights who skirmished with the English advanced guard retreated into Romorantin, and when the Black Prince heard of this he said: "Let us go there; I should like to see them a little nearer". He inspected the fortress in person and sent his friend Chandos to summon the garrison to surrender. The place was defended by Boucicault and other