The British Navy wanted a battleship by early 1944 for use in the Far Eastern fleet to counter Japanese battleships under development. It was felt that the Vanguard could be manned by the Royal Australian Navy.
Three designs were submitted on July 17, 1939. However, with the start of World War II, discussion ceased on September 11, 1939. It was picked back up in February 1940. After other pauses the final design was approved on April 17, 1941, and ordered on March 14, 1941.
The Vanguard was similar in layout to the King George V class.
The HMS Vanguard was to use the 15" turrets that used to be mounted in the HMS Courageous and HMS Glorious. The 15" guns could fire a 1,938 lb shell at 2,458'/sec.