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
HMS Agincourt (1865) double bottom underneath the engine and boiler rooms. "Agincourt" was considered "an excellent sea-boat and a steady gun platform, but unhandy under steam and practically unmanageable under sail" as built. The ship's steadiness was partially a result of her metacentric height of . "Agincourt" had one 2-cylinder horizontal return connecting rod-steam engine, made by Maudslay, driving a single propeller using steam provided by 10 rectangular fire-tube boilers. It produced a total of during the ship's sea trials on 12 December 1865 and "Agincourt" had a maximum speed of . The ship carried of coal, enough to steam at . "Agincourt"