Although not an official national flag, the Z signal flag played a major role in Japanese naval history. On May 27, 1905, Admiral Heihachirō Tōgō of the "Mikasa" was preparing to engage the Russian Baltic Fleet. Before the Battle of Tsushima began, Togo raised the Z flag on the "Mikasa" and engaged the Russian fleet, winning the battle for Japan. The raising of the flag said to the crew the following: "The fate of Imperial Japan hangs on this one battle; all hands will exert themselves and do their best." The Z flag was also raised on the aircraft carrier "Akagi" on the eve of the Japan's attack on Pearl Harbor, Hawaii, in December 1941.