Military career
Prince Hiroyasu entered the Imperial Japanese Naval Academy on 5 April 1886, but resigned in September 1889 and moved to Germany. He enrolled in the Naval Academy of the Kaiserliche Marine on 8 April 1892. Promoted to midshipman (Fähnrich zur See) on 30 March 1893 and to ensign (Oberfähnrich zur See) on 20 April 1894, he graduated from the academy on 15 August 1895 and returned to service in the IJN. He spoke fluent German. He then served aboard the cruisers Itsukushima and Matsushima. On 1 December 1897, he was promoted to sub-lieutenant and assigned to the battleship Fuji, receiving a promotion to lieutenant on 27 December. Promoted to lieutenant-commander on 29 July 903, he served in the Russo-Japanese War (1904–05), and sustained wounds aboard the battleship Mikasa in the Battle of the Yellow Sea (August 1904). He later served as executive officer on the cruiser Niitaka, the battleship Okinoshima, and cruisers Naniwa and Nisshin. He was awarded the Order of the Golden Kite, 4th class, for his services in the Russo-Japanese War, and was promoted to commander on 28 September 1906.
He studied in Great Britain from 1907 to 1910 and upon his return to Japan was promoted to captain on 1 December 1910. He commanded the cruiser Takachiho (1910), and later the Asahi and the battlecruiser Ibuki. Promoted to rear admiral on 31 August 1913, he rose to vice admiral on 1 December 1916 and to full admiral on 1 December 1922. He was a member of the Supreme War Council from 1920 onward. He was a strong supporter of the Fleet Faction within the Navy, pushing for the cancellation of the Washington Naval Agreement and the building of a more powerful navy.
Prince Hiroyasu succeeded his father as the twenty-third head of the house of Fushimi in 1923. He was appointed commander of the Sasebo Naval District in 1924. Admiral Prince Fushimi became the chief of the Imperial Japanese Navy General Staff on 2 February 1932, replacing Admiral Abo Kiyokazu, and held the post until 9 April 1941.
Prince Fushimi received the largely honorary rank of marshal admiral on 27 May 1932, and the Collar of the Supreme Order of the Chrysanthemum in 1934.
While he was Chief of Staff of the Imperial Japanese Navy, the Imperial Japanese Navy Air Service used strategic bombing against Chinese cities including Shanghai and Chongqing. The bombing of Nanjing and Guangzhou, which began on 22–23 September 1937, resulted in widespread international condemnation of Japan and a resolution against Japan by the Far Eastern Advisory Committee of the League of Nations.
As Chief of Staff, he supported the "southward advance" into northern French Indochina and the Dutch East Indies.
In 1945, the Americans listed Hiroyasu as a major war criminal suspect. Although he was reported dead in the War Crimes Office list, he was alive but sick.
