Chivalry and Betrayal: The Hundred Years' War to confirm his legitimacy resumed the war with France now led by a king who was insane. In 1415 he landed at Harfleur which fell after a long siege weakening the English army. Against advice Henry led his army on a chevauchée to English held Calais but was intercepted by a far larger French army at Agincourt and at the ensuing battle Henry's archers killed the cream of French nobility. At Agincourt Henry V, the son of a usurper, had proved his right to be King and he was determined to regain Normandy and recreate the Duchy and landed in
Marie of Brittany, Lady of La Guerche husband John had five children:<br> In January 1414, Charles IV of France raised the county of Alençon to a duchy, and made Marie's husband, John, the first duke of Alençon. Marie's husband died at the Battle of Agincourt, where he fought alongside the King of France. After the death of her husband in 1415, Marie was forced to flee Normandy, where she had been living prior to the Battle of Agincourt. Her son, John, became John II of Alençon and was captured at the Battle of Verneuil in 1424. He paid for his freedom from the English in 1427, and