Between the 1890s and 1940s, the Imperial Japanese Navy (IJN) built a series of battleships as it expanded its fleet. Previously, the Empire of Japan had acquired a few ironclad warships from foreign builders, although it had adopted the Jeune École naval doctrine which emphasized cheap torpedo boats and commerce raiding to offset expensive, heavily armored ships. To counter the Imperial Chinese Beiyang Fleet in the early 1890s, however, Japan ordered two Fuji-class battleships from Great Britain as Japan lacked the technology and capability to construct its own vessels. Combat experience in the First Sino-Japanese War of 1894–1895 convinced the IJN that its doctrine was untenable, leading to a ten-year naval construction program that called for a total of six battleships and six armored cruisers (the Six-Six Fleet). The two ships of the Shikishima class and the battleships Asahi and Mikasa were also purchased from Great Britain. Aware that they could not outbuild the Americans or British, the IJN decided that their ships would always be qualitatively superior to offset their quantitative inferiority.^[1]

To counter reinforcement of the Russian Empire's Pacific Squadron as tensions rose between the Russians and the Japanese over control of Korea and Manchuria in the early 1900s, Japan ordered the two battleships of the Katori class in 1903, the last battleships ordered from abroad.^[2] To preempt further reinforcements before their own ships were completed, they began the Russo-Japanese War in 1904 with a surprise attack on the Russian base at Port Arthur. Shortly after the war began, the IJN ordered the two ships of the Satsuma class, the first battleships to be built in Japan.^[3] The Imperial Japanese Army captured Port Arthur, along with the surviving ships of the Pacific Squadron by the end of the year. The Russians had dispatched the bulk of their Baltic Fleet to relieve Port Arthur, which reached the Korea Strait in May 1905 and was virtually annihilated by the IJN in the Battle of Tsushima.^[4] During the war, Japan captured a total of five Russian pre-dreadnought battleships. They were repaired and commissioned into the Japanese fleet, two of which were later sold back to Russia during World War I, as the two countries were by then allies. The magnitude of the victory at Tsushima caused the leadership of the IJN to believe that a surface engagement between the main fleets was the only decisive battle in modern warfare and would be decided by battleships armed with the largest guns.^[5]

After the war, the Japanese Empire immediately turned its focus to the two remaining rivals for imperial dominance in the Pacific Ocean, Britain and the United States,^[6] believing that conflict would inevitably arise between Japan and at least one of its two main rivals. Accordingly, the 1907 Imperial Defense Policy called for the construction of a battle fleet of eight modern battleships and eight battlecruisers.^[7] This was the genesis of the Eight-Eight Fleet Program, the development of a cohesive battle line of sixteen capital ships.^[8] The launch of HMS Dreadnought in 1906 and the battlecruiser Invincible the following year by the Royal Navy raised the stakes^[9] and complicated Japan's plans as they rendered all existing battleships and armored cruisers obsolete, forcing Japan to restart the Eight-Eight plan with dreadnought battleships and battlecruisers.^[10][11] This began with the Kawachi class in 1907, followed by the Fusō and Ise classes in the 1910s. Japan ordered its seventh and eighth dreadnoughts with the Nagato class in 1916 and 1917.^[12]

In 1919, American President Woodrow Wilson announced the resumption of the 1916 naval construction program and the Japanese ordered eight fast battleships of the Kii and Number 13 classes in response.^[13] The prospect of a new massively expensive arms race between the United States, Britain and Japan after the war caused the three powers to agree to the Washington Naval Treaty which limited Japan to a ratio of 3:5:5 in battleship tonnage to the United States and Britain. The treaty forced the IJN to dispose of all of its pre-dreadnoughts and the oldest dreadnoughts; the ships then under construction had to be broken up or sunk as targets. Furthermore, the treaty mandated a building holiday that barred the construction of new battleships for ten years. During this period, opponents of the Washington Naval Treaty and its successors had taken control of the upper echelons of the IJN^[14] and rebuilt the Kongō-class battlecruisers into fast battleships and modernized the existing ships.^[15] Coupled with the growth of ultranationalism and dominance of the government by the military, the government decided to withdraw from the treaty regime when it expired in 1936. Planning by the Navy General Staff for the post-treaty era began in 1934 and included five large battleships armed with nine 460 mm (18.1 in) guns; these ships became the Yamato class.^[16] While the Yamatos were under construction in the late 1930s, the IJN began designing a successor class, the Design A-150 armed with 51 cm (20.1 in) guns, but never laid any down as they prepared for war and other ships had higher priority.^[17]

Key

Pre-Dreadnoughts

Fuji class

The two Fuji-class (Kanji: 富士型戦艦; Rōmaji: Fuji-gata) ships, Fuji and Yashima, were the IJN's first battleships, ordered from Britain in response to two new German-built Chinese ironclad warships. The ships were designed as smaller versions of the British Royal Sovereign class, although they were slightly faster and had a better type of armor.^[18]

As part of the 1st Fleet the Fujis participated in fighting off Port Arthur on 9–10 March 1904, wherein Fuji sustained light damage and Yashima was undamaged.^[19] On 15 May Yashima struck two naval mines and foundered.^[20] Fuji participated in the Battle of the Yellow Sea in August and was then slightly damaged during the Battle of Tsushima in May 1905.^[21] She was credited with the shot that caused the magazine explosion that destroyed the battleship Borodino.^[22] In October 1908, Fuji hosted the American ambassador to Japan and some senior officers of the Great White Fleet,^[23] and was later reclassified as a coast defense ship in 1910. The ship was disarmed and converted into an accommodation ship in 1922. Fuji was sunk by American aircraft in 1945 and scrapped in 1948.^[24]

Shikishima class

The Shikishima class (Kanji: 敷島型戦艦; Rōmaji: Shikishima-gata senkan) was designed as a more powerful version of the Royal Navy's Majestic-class battleship.^[30] The ships were also assigned to the 1st Fleet before the Russo–Japanese War, were present at the Battle of Port Arthur and were slightly damaged during the action. Hatsuse struck one of the mines that the Russians laid in May 1904 and sank following a magazine explosion.^[31] Shikishima fought in the Battle of the Yellow Sea, only being damaged by a misfiring 12-inch shell,^[32] and then participated in the Battle of Tsushima where she was hit nine times, suffered another misfire from one of her main guns, and, together with the battleship Mikasa, sank the Russian battleship Oslyabya.^[33] Shikishima spent the duration of World War I assigned to the Sasebo Naval District,^[34] and was demilitarized after the Washington Naval Treaty was signed in 1922.^[35] She was used as a training hulk at Sasebo until she was broken up in 1948.^[36]

Asahi

Asahi was a slightly improved version of the British Formidable-class battleships.^[34] She became the flagship of the IJN's Standing Fleet and was later assigned to the 1st Fleet when the Combined Fleet reformed in 1903.^[41][42] At the start of the Russo–Japanese War, Asahi took part in the Battle of Port Arthur and was not damaged by Russian fire. At the Battle of the Yellow Sea, the ship was moderately damaged, although she hit and damaged Poltava and Tsesarevich in return.^[43] Asahi struck a mine two months later near Port Arthur, but was repaired in time for the Battle of Tsushima. There, she helped disable the battleship Knyaz Suvorov and dueled with the battleships Borodino and Oryol, taking no damage.^[44]

She was a gunnery training ship for most of World War I until being rearmed in 1917 in time to escort troop transports during Japan's intervention in the Russian Civil War.^[35] Asahi was converted into a noncombat vessel during the 1920s and was then made a repair ship in 1937.^[42] On the night of 25–26 May 1942, Asahi was torpedoed and sunk by the submarine USS Salmon off modern-day Vietnam.^[41]

Mikasa

Mikasa was also an improved version of the Formidable-class battleships and only differed in minor respects from Asahi.^[34] The ship served as the 1st Fleet flagship throughout the Russo-Japanese War. She participated in the Battle of Port Arthur on the second day of the war and the Battles of the Yellow Sea and Tsushima.^[43] During the latter battle, the ship was hit many times, but was only lightly damaged.^[48] Days after the end of the war, Mikasa's magazine accidentally exploded and sank the ship.^[49] She was salvaged and her repairs took over two years to complete.^[50] Afterward, the ship served as a coast-defense ship during World War I and supported Japanese forces when they intervened in the Russian Civil War.^[34] After the Washington Naval Treaty was ratified in 1922 Mikasa was preserved as a museum ship. She was badly neglected during the post-World War II occupation of Japan and required extensive refurbishing in the late 1950s, but has only partially been restored.^[51] Mikasa is the only surviving example of a pre-dreadnought battleship in the world.^[52]

Tango

Tango was laid down as the Russian battleship Poltava (Russian: Полтава), the second of three Petropavlovsk-class pre-dreadnought battleships. The ship was assigned to the Pacific Squadron shortly after her completion and based at Port Arthur from 1901.^[56] During the Russo-Japanese War, she participated in the Battle of Port Arthur and was heavily damaged during the Battle of the Yellow Sea.^[57][58] Sunk by Japanese artillery during the subsequent Siege of Port Arthur in December 1904, she was refloated by the IJN after the war and subsequently renamed Tango.^[59][60] During World War I, she bombarded German fortifications during the Siege of Tsingtao.^[61] The Japanese government sold Tango back to the Russians in 1916. She was renamed Chesma (Чесма) as her former name had been given to a new ship.^[60][62] Her crew declared for the Bolsheviks in October 1917,^[63] but saw no action in the Russian Civil War owing to her poor condition, and she was ultimately scrapped in 1924.^[62][64]

Sagami and Suwo

Sagami and Suwo were originally the Russian Peresvet-class battleships Peresvet (Пересвет) and Pobeda (Победа) respectively.^[69] The design of the Peresvet class was inspired by the British second-class battleships of the Centurion class. The British ships were intended to defeat commerce-raiding armored cruisers like the Russian ships Rossia and Rurik, and the Peresvet class was designed to support their armored cruisers.^[70]

The sisters were sunk during the Siege of Port Arthur and were salvaged by the IJN afterward. Because of their lighter armament than the other captured battleships, they were rated as coastal-defense ships.^[71] During World War I, Suwo was the flagship of the Japanese squadron during the Siege of Tsingtao and then of the 2nd Fleet before becoming a gunnery-training ship in 1916. Sagami was sold back to the Russians that same year and resumed her former name. While en route to northern Russia, the ship struck two mines in the Mediterranean and sank.^[72] Suwo was disarmed in 1922 in accordance with the terms of the Washington Naval Treaty and was probably scrapped afterward.^[71]

Hizen

Hizen, originally Retvizan (Ретвизан), was a Russian pre-dreadnought battleship built in America before the Russo-Japanese War because Russian shipyards were already at full capacity.^[78] The ship was torpedoed during the Battle of Port Arthur, but was repaired in time to participate in the Battle of the Yellow Sea, during which she was lightly damaged.^[32][79] She was sunk during the Siege of Port Arthur and salvaged by the IJN.^[80] During World War I, Hizen was sent to reinforce the weak British squadron off British Columbia, but diverted to Hawaii after reports of a German gunboat there were received. The ship was unsuccessfully sent to search for other German ships after the Americans interned the gunboat in November 1914. After the war she supported the Japanese intervention in the Russian Civil War and was disarmed in 1922 as required by the terms of the Washington Naval Treaty. Hizen was sunk as a target in 1924.^[81][82]

Iwami

Iwami was built shortly before the Russo-Japanese War for the Imperial Russian Navy as Oryol (Орёл), one of five Borodino-class battleships. Together with three of her sisters, she voyaged half-way around the world to participate in the Battle of Tsushima.^[87] Moderately damaged during the battle,^[88] the ship was surrendered to the IJN the following day.^[89] The Japanese rebuilt her from 1905 to 1907 and she was assigned to the 1st Fleet, although the ship was reclassified as a coast defense ship in 1912. Iwami participated in the Siege of Tsingtao in 1914 after Japan declared war on Imperial Germany and then became a guardship. She became the flagship of the 5th Division of the 3rd Fleet in 1918 and supported the Japanese intervention in the Russian Civil War. Iwami briefly became a training ship before she was disarmed in 1922 and was sunk as a target two years later.^[90][91][92]

Katori class

The pair of Katori-class pre-dreadnoughts were the last Japanese battleships to be built overseas.^[97] The design of the Katori class was a modified and improved version of the Royal Navy's King Edward VII-class battleships.^[98] Completed after the end of the Russo–Japanese War, the ships never saw combat. Katori had a major fire in one of her secondary-gun turrets in 1907 that killed 34 men and wounded 8 others.^[99] While they saw no action during World War I, they both participated in Japan's intervention in Siberia in 1918.^[100][101] In 1921, the sisters carried Crown Prince Hirohito on his tour of Europe where he met King George V.^[102] Under the terms of the Washington Naval Treaty, both ships were disarmed and scrapped between 1923 and 1925.^[101]

Satsuma class

The Satsuma-class battleships, Satsuma and Aki, were the first battleships to be built in Japan. They marked a transitional stage in battleship design,^[3] as the sisters were intended to mount a dozen 12-inch (305 mm) guns. Material shortages in Japan and the expense of construction led to a redesign that armed the sisters with four 12-inch and a dozen 10-inch (254 mm) guns.^[107] If built as planned, the Satsuma class would have been the world's first "all big-gun" battleships.^[97] Satsuma was powered traditionally with two vertical triple-expansion engines, but Aki was the first Japanese battleship to use steam turbines.^[108]

The introduction of HMS Dreadnought in 1906 ensured that the Satsuma class was obsolete before the ships were even launched. Nevertheless, Aki was launched on 15 November, while Satsuma followed on 15 April 1907.^[109] Satsuma would go on to serve as Rear Admiral Tatsuo Matsumura's flagship in the Second South Seas Squadron as it seized the German possessions of the Caroline and the Palau Islands in October 1914 in the opening months of World War I. Satsuma would later be refitted at Sasebo Naval Arsenal in 1916 and served with the 1st Squadron for the rest of the war. Aki was also assigned to the 1st Squadron until she was transferred to the 2nd Battleship Squadron in 1918.^[97] Both ships were sunk as targets by Nagato and Mutsu in 1924.^[110]

Dreadnought battleships

Kawachi class

The Kawachi class (Kanji: 河内型戦艦; Rōmaji: Kawachi-gata senkan), Kawachi and Settsu, were a pair of dreadnought battleships ordered in the Navy's Warship Supplement Program after the Russo-Japanese War.^[111] They were the IJN's first dreadnoughts and marked one of the first steps in achieving Japan's recently adopted Eight-Eight Fleet Program.^[112] The sisters were armed with four 50-caliber 12-inch and eight 45-caliber 12-inch main guns,^[113] arranged in the hexagonal layout used by the German dreadnoughts of the Nassau and Helgoland classes.^[114] They had originally been designed with a dozen 45-caliber guns, but after the IJN received word that the Royal Navy had adopted the more powerful and expensive 50-caliber guns, it upgraded the four centerline guns to the longer caliber as it could not afford to upgrade all of them.^[115]

Settsu and Kawachi bombarded German fortifications at Tsingtao during the Battle of Tsingtao in 1914, but saw no other combat in World War I. Kawachi sank in 1918 after an explosion in her ammunition magazine with the loss of over 600 officers and crewmen.^[116] Settsu was disarmed in 1922 and converted into a target ship. She was heavily damaged in 1945 by American carrier aircraft and eventually beached to avoid sinking. The ship was subsequently scrapped in 1946–1947.^[117]