World War II: U.S. forces sank the Japanese battleship Yamato during Operation Kikusui I in the East China Sea.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

Yamato was the lead ship of her class of battleships built for the Imperial Japanese Navy (IJN) shortly before World War II. She and her sister ship, Musashi, were the heaviest and most powerfully armed battleships ever constructed, displacing nearly 72,000 tonnes at full load and armed with nine 46 cm (18.1 in) Type 94 main guns, which were the largest guns ever mounted on a warship.

Operation Kikusui I , literally Operation Chrysanthemum Water 1, best known as Operation Ten-Go , literally Operation Heaven, was the last major Japanese naval operation in the Pacific Theater of World War II. In April 1945, the Japanese battleship Yamato, the largest battleship in the world, and nine other Japanese warships, embarked from Japan for a suicide attack on Allied forces engaged in the Battle of Okinawa. The Japanese force was attacked by U.S. carrier-borne aircraft before it could reach Okinawa; Yamato and five other Japanese warships were sunk while 10 American aircraft were shot down. Several ships in the U.S. carrier task force suffered moderate damage from aerial kamikaze attacks while 100 Japanese planes were lost. Operation Kikusui I, best known as Operation Ten-Go, refers specifically to Yamato's sortie, while Operation Kikusui refers specifically to all Japanese kamikaze operations during the entire Okinawa campaign.