The IJN Musashi (武蔵) was a battleship belonging to the Imperial Japanese Navy. With her sister ship Yamato, she was a member of the largest and most heavily armoured class of battleships ever constructed.
She formed part of Vice-Admiral Takeo Kurita's Centre Force along with Yamato at the Battle of Leyte Gulf. During the battle, on October 22,1944 she was attacked and sunk by American carrier-based aircraft armed with bombs and torpedoes, taking more than 1000 of her 2900 crew with her.
For more details on this class of ship, see the entry for Yamato.