Battleships in World War II part of Operation Neptune, in support of the D-Day landings in June 1944. D-Day also saw the deliberate sacrifice of two old dreadnoughts ( and ), which were scuttled as part of the breakwater around the Allied Mulberry harbours. The sinking of "Prince of Wales" and "Repulse" off the coast of Malaya in 1941 demonstrated that even the most modern battleships could not hold off aerial attacks without decent aerial defenses. The British HACS fire control system had been rendered inoperable by the extreme heat and humidity of the Malaya tropical climate, and the anti-aircraft artillery had managed to shoot
D-Day (military term) originally set for June 5, 1944, but bad weather and heavy seas caused U.S. Army General Dwight David Eisenhower to delay until June 6 and "that" date has been popularly referred to ever since by the short title "D-Day". Because of the connotation with the invasion of Normandy, planners of later military operations sometimes avoided the term to prevent confusion. For example, Douglas MacArthur's invasion of Leyte began on "A-Day", and the invasion of Okinawa began on "L-Day". The Allies' proposed invasions of Japan would have begun on "X-Day" (on Kyūshū, scheduled for November 1945) and "Y-Day" (on Honshū, scheduled