What was Isoroku Yamamoto's role in "the most stunning and decisive blow in the history of naval warfare."?
Isoroku Yamamoto Isoroku Yamamoto (山本 五十六 , Yamamoto Isoroku , April 4, 1884 – April 18, 1943) was a Japanese Marshal Admiral of the Navy and the commander-in-chief of the Combined Fleet during World War II until his death.
Jun'yō Maru Jun'yō Maru (順陽丸 ) was a Japanese cargo ship (one of the "hell ships") that was attacked and sunk in 1944 by the British submarine  , resulting in the loss of over 5,000 lives.