Here's What You Need to Remember: At 14:23, it happened. Yamato’s forward internal magazines detonated in a spectacular fireball. It was like a tactical nuclear weapon going off. In early 1945, the Imperial Japanese Navy made a difficult decision: it would sacrifice the largest, most powerful battleships ever built to protect Okinawa, the gateway to Japan’s Home Islands. The decision sealed the fate of the battleship Yamato and its crew, but ironically did nothing to actually protect the island from Allied invasion. The battleship Yamato was among the largest and most powerful battleships of all time. Yamato has reached nearly mythical status, a perfect example of Japan’s fascination with doomed, futile heroics. Built in 1937 at the Kure Naval Arsenal near Hiroshima, it was constructed in secrecy to avoid alarming the United States. Japan had recently withdrawn from the Washington Naval Treaty, which limited battleship tonnages, and was free to build them as large as it wanted.