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.
Imperial Japanese Navy
During the Russo-Japanese war, Japan also made frantic efforts to develop and construct a fleet of submarines. Submarines had only recently become operational military engines, and were considered to be special weapons of considerable potential. Naval losses for the Japanese Navy during the war amounted to two battleships, four cruisers, one armored cruiser, seven destroyers, and at least 10 torpedo boats; the majority of them were lost due to hitting Russian mines.