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.
Hundred Years' War
Henry IV of England died in 1413 and was replaced by his eldest son Henry V. The mental illness of Charles VI of France allowed his power to be exercised by royal princes whose rivalries caused deep divisions in France. Henry V was well aware of these divisions and hoped to exploit them. In 1414 while he held court at Leicester, he received ambassadors from Burgundy. Henry accredited envoys to the French king to make clear his territorial claims in France; he also demanded the hand of Charles VI's youngest daughter Catherine of Valois. The French rejected his demands, leading Henry to prepare for war.