On 17 September 1944, General Kurt Student, the founder of Nazi Germany's parachute forces, heard the growing roar of aero engines. He went out on to his balcony above the flat landscape of southern Holland to watch the vast air armada of Dakotas and gliders, carrying the British 1st Airborne and the American 101st and 82nd Airborne Divisions. He gazed up in envy at the greatest demonstration of paratroop power ever seen.