Hundred Years' War (1415–53)
By 1449, the French had retaken Rouen. In 1450 the Count of Clermont and Arthur de Richemont, Earl of Richmond, of the Montfort family (the future Arthur III, Duke of Brittany) caught an English army attempting to relieve Caen at the Battle of Formigny and defeated it. The English army was attacked from the flank and rear by Richemont's force just as they were on the verge of beating Clermont's army. The French proceeded to capture Caen on July 6 and Bordeaux and Bayonne in 1451. The attempt by Talbot to retake Guyenne, though initially welcomed by the locals, was crushed by Jean Bureau and his cannons at the Battle of Castillon in 1453 where Talbot had led a small Anglo-Gascon force in a frontal attack on an entrenched camp. This is considered the last battle of the Hundred Years' War.
Duchy of Aquitaine
Having suppressed a revolt in his new possession, Henry gave it to his son Richard. When Richard died in 1199, it reverted to Eleanor, and on her death five years later, it was absorbed into the English crown and henceforward followed the fortunes of the other English possessions in France, such as Normandy and Anjou, ultimately leading to the Hundred Years' War between the French and English crowns.