Submarines of the Imperial Japanese Navy
Imperial Japanese Navy submarines originated with the purchase of five Holland type submarines from the United States in 1904. Japanese submarine forces progressively built up strength and expertise, becoming by the beginning of World War II one of the world's most varied and powerful submarine fleets.
Japanese submarine tender Komahashi
The Imperial Japanese Navy received its first submarines during the Russo-Japanese War, but these vessels were not operational until after the war ended. During the post-war period, submarine warfare was given a low priority for development, as the early submarines were regarded as unsafe, and useful only for short-range coastal point defense.