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.
Late Middle Ages
From 1337, England's attention was largely directed towards France in the Hundred Years' War. Henry V's victory at the Battle of Agincourt in 1415 briefly paved the way for a unification of the two kingdoms, but his son Henry VI soon squandered all previous gains. The loss of France led to discontent at home. Soon after the end of the war in 1453, the dynastic struggles of the Wars of the Roses (c. 1455–1485) began, involving the rival dynasties of the House of Lancaster and House of York.