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
Battle of Agincourt and various prominent French noblemen of the Armagnac party. This battle is notable for the use of the English longbow in very large numbers, with the English and Welsh archers making up nearly 80 percent of Henry's army. The devastation of the French cavalry at their hands signaled the decline of cavalry and the increasing dominance of ranged weapons on the battlefield. Agincourt is one of England's most celebrated victories and was one of the most important English triumphs in the Hundred Years' War, along with the Battle of Crécy (1346) and Battle of Poitiers (1356). It forms the centrepiece