WWII: Battle of Midway naval fleet size 1942
The Battle of Midway is viewed by many as the turning point in the Pacific War, due to the heavy losses inflicted upon the Imperial Japanese Navy, and the knock on effect this had in the Pacific theater. In particular, the Japanese Navy lost all four of the aircraft carriers that took part in the battle, while the U.S. lost only one. This was in addition to the two Japanese aircraft carriers were lost or damaged one month previously in the Battle of the Coral Sea. These battles saw the aircraft carrier replace the battleship as the central vessel of the modern navy, and the destruction of Japan's flagship carriers saw the U.S. gain the numerical advantage in the Pacific, which they maintained until the war's end.