However, the kings of England remained dukes of Aquitaine. When Philip IV died, his nephew, Philip I count of Valois mounted the throne of France in the end, as Philip VI. Philip IV had married Jean of Champagne, who brought Champagne with her into the royal domain (1284). They had two sons but a new series of conflicts, known as the Hundred Years' War, was provoked by the claim of Edward III of England, grandson of Philip IV through Edward's mother. Edward's aim was to supplant Philip VI. French armies suffered heavy defeats at Crécy (1346) and Poitiers (1356). Later, a third serious defeat was suffered at Agincourt (1415). Having temporarily lost territory as a result of the Treaty of Brétigny, the kingdom was again divided by the Treaty of Tours (1420). But a new spirit was born in Joan of Arc who obliged the English king to raise the Siege of Orléans (1429). Having been crowned at Reims, Charles VII returned to Paris and finally established his authority in the South West, that is to say Aquitaine, taking Bordeaux and Bayonne (1453) from the English king.