The was the main battleship

Battleship

A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

 fleet of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

.

History

First established on 28 December 1903, the IJN 1st Fleet was created during the Russo-Japanese War

Russo-Japanese War

The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...

 when the Imperial General Headquarters

Imperial General Headquarters

The as part of the Supreme War Council was established in 1893 to coordinate efforts between the Imperial Japanese Army and Imperial Japanese Navy during wartime...

 divided the Readiness Fleet into a mobile strike force of cruiser

Cruiser

A cruiser is a type of warship. The term has been in use for several hundreds of years, and has had different meanings throughout this period...

s and destroyer

Destroyer

In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

s to pursue the Imperial Russian Navy

Imperial Russian Navy

The Imperial Russian Navy refers to the Tsarist fleets prior to the February Revolution.-First Romanovs:Under Tsar Mikhail Feodorovich, construction of the first three-masted ship, actually built within Russia, was completed in 1636. It was built in Balakhna by Danish shipbuilders from Holstein...

's Vladivostok

Vladivostok

The city is located in the southern extremity of Muravyov-Amursky Peninsula, which is about 30 km long and approximately 12 km wide.The highest point is Mount Kholodilnik, the height of which is 257 m...

-based cruiser squadron (IJN 2nd Fleet), while the remaining bulk of the Japanese fleet (the IJN 1st Fleet) continued to blockade Port Arthur

Lüshunkou

Lüshunkou is a district in the municipality of Dalian, Liaoning province, China. Also called Lüshun City or Lüshun Port, it was formerly known as both Port Arthur and Ryojun....

 in hopes of luring the battleship

Battleship

A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

s of the Russian Pacific Fleet out into a classic line-of-battle confrontation. The two fleets were combined into the Combined Fleet

Combined Fleet

The was the main ocean-going component of the Imperial Japanese Navy. The Combined Fleet was not a standing force, but a temporary force formed for the duration of a conflict or major naval maneuvers from various units normally under separate commands in peacetime....

 for the final Battle of Tsushima

Battle of Tsushima

The Battle of Tsushima , commonly known as the “Sea of Japan Naval Battle” in Japan and the “Battle of Tsushima Strait”, was the major naval battle fought between Russia and Japan during the Russo-Japanese War...

.
The decisive victory of the Japanese fleet over the Imperial Russian Navy

Imperial Russian Navy

The Imperial Russian Navy refers to the Tsarist fleets prior to the February Revolution.-First Romanovs:Under Tsar Mikhail Feodorovich, construction of the first three-masted ship, actually built within Russia, was completed in 1636. It was built in Balakhna by Danish shipbuilders from Holstein...

 at the Battle of Tsushima validated the doctrine of the "decisive victory", or kantai kessen

Kantai kessen

The was a naval strategy adopted by the Imperial Japanese Navy following the Russo-Japanese War. It called on the use of a strong battleship force, which would destroy an invading fleet as it approached Japan after suffering losses through attrition as it penetrated Japanese perimeter defenses.The...

as stipulated by naval theorists such as Alfred Thayer Mahan

Alfred Thayer Mahan

Alfred Thayer Mahan was a United States Navy flag officer, geostrategist, and historian, who has been called "the most important American strategist of the nineteenth century." His concept of "sea power" was based on the idea that countries with greater naval power will have greater worldwide...

 and Satō Tetsutarō

Sato Tetsutaro

-Notes:...

 in the eyes of the Imperial Japanese Navy General Staff

Imperial Japanese Navy General Staff

The was the highest organ within the Imperial Japanese Navy. In charge of planning and operations, it was headed by an Admiral headquartered in Tokyo.-History:...

, and future naval procurement and deployment was centered around refinements of this doctrine. The Mahanian objective was to build a fleet in being

Fleet in being

In naval warfare, a fleet in being is a naval force that extends a controlling influence without ever leaving port. Were the fleet to leave port and face the enemy, it might lose in battle and no longer influence the enemy's actions, but while it remains safely in port the enemy is forced to...

, a naval force kept deliberately in strategic reserve

Strategic reserve

For the military term see: Military reserveA strategic reserve is a term used to describe a reserve of a commodity or items, held back from normal use by governments, organisations or business in pursuance of a particular strategy or to cope with unexpected events.A strategic reserve can be:*...

, as secondary forces based on cruisers and destroyers waged a campaign of attrition

War of Attrition

The international community and both countries attempted to find a diplomatic solution to the conflict. The Jarring Mission of the United Nations was supposed to ensure that the terms of UN Security Council Resolution 242 would be observed, but by late 1970 it was clear that this mission had been...

 against an approaching enemy, who would then be destroyed in a climatic final battle similar to the Battle of Tsushima.
As a result of this doctrine, although individual ships and task forces were dispatched on occasion for specific combat operations, the main force in the Imperial Japanese Navy was mostly held in reserve from the time of its inception until near the end of World War II.

Commanders of the IJN 1st Fleet

Commander in chief

	Rank	Name	Date
1	Fleet Admiral	Marquis Heihachiro Togo Togo Heihachiro Fleet Admiral Marquis was a Fleet Admiral in the Imperial Japanese Navy and one of Japan's greatest naval heroes. He was termed by Western journalists as "the Nelson of the East".-Early life:...	28 Dec 1903 - 20 Dec 1905
2	Admiral	Shichiro Kataoka	20 Dec 1905 - 22 Nov 1906
3	Vice Admiral	Marquis Shinichi Arima	22 Nov 1906 - 26 May 1908
4	Fleet Admiral	Baron Goro Ijuin Ijuin Goro -External links:...	26 May 1908 - 1 Dec 1909
5	Admiral	Baron Hikonojo Kamimura Kamimura Hikonojo Baron was an early admiral of the Imperial Japanese Navy later commanding the IJN 2nd Fleet during the Russo-Japanese War, most notably at the Battle off Ulsan and Tsushima.-Biography:...	1 Dec 1909 - 1 Dec 1911
6	Admiral	Baron Shigeto Dewa Dewa Shigeto - Notes :...	1 Dec 1911 - 1 Dec 1913
7	Fleet Admiral	Viscount Tomosaburō Katō Kato Tomosaburo Viscount was a career officer in the Imperial Japanese Navy, cabinet minister, and Prime Minister of Japan from 12 June 1922 to 24 August 1923.-Biography:...	1 Dec 1913 - 10 Aug 1915
8	Admiral	Koichi Fujii	10 Aug 1915 - 23 Sep 1915
9	Admiral	Motaro Yoshimatsu	23 Sep 1915 - 1 Dec 1917
10	Admiral	Baron Gentaro Yamashita	1 Dec 1917 - 1 Dec 1919
11	Admiral	Tanin Tamaya	1 Dec 1919 - 24 Aug 1920
12	Admiral	Sojrio Tochinai	24 Aug 1920 - 27 Jul 1922
13	Admiral	Isamu Takeshita Isamu Takeshita was an admiral in the Imperial Japanese Navy. He was also a diplomat whose accomplishments included helping end the Russo-Japanese War favorably for Japan and obtaining former German possessions in the Pacific for Japan following World War I...	27 Jul 1922 - 27 Jan 1924
14	Admiral	Baron Kantarō Suzuki Kantaro Suzuki Baron was an admiral in the Imperial Japanese Navy, member and final leader of the Taisei Yokusankai and 42nd Prime Minister of Japan from 7 April-17 August 1945.-Early life:...	27 Jan 1924 - 1 Dec 1924
15	Admiral	Keisuke Okada Keisuke Okada was an admiral in the Imperial Japanese Navy, politician and the 31st Prime Minister of Japan from 8 July 1934 to 9 March 1936.-Early life:Okada was born in what is now Fukui Prefecture to an ex-samurai family. He attended the 15th class of the Imperial Japanese Naval Academy, graduating 7th out of...	1 Dec 1924 - 10 Dec 1926
16	Admiral	Hiroharu Kato	10 Dec 1926 - 10 Dec 1928
17	Admiral	Saburo Hyakutake	10 Dec 1928 - 11 Nov 1929
18	Admiral	Eisuke Yamamoto	11 Nov 1929 - 1 Dec 1931
19	Admiral	Seizo Kobayashi	1 Dec 1931 - 15 Nov 1933
20	Admiral	Nobumasa Suetsugu	15 Nov 1933 - 15 Nov 1934
21	Admiral	Sankichi Takahashi Sankichi Takahashi was an Admiral of the Imperial Japanese Navy. After the Washington Naval Treaty of 1922 Takahashi, an important figure of IJN's Fleet Faction, made a swift career, from commander of an obsolete cruiser in 1923 to commander of the Combined Fleet in 1934...	15 Nov 1934 - 1 Dec 1936
22	Admiral	Mitsumasa Yonai Mitsumasa Yonai was an admiral in the Imperial Japanese Navy, and politician. He was the 37th Prime Minister of Japan from 16 January to 22 July 1940.-Early life & Naval career:...	1 Dec 1936 - 2 Feb 1937
23	Fleet Admiral	Osami Nagano	2 Feb 1937 - 1 Dec 1937
24	Admiral	Zengo Yoshida Zengo Yoshida was an admiral in the Imperial Japanese Navy.-Biography:Yoshida was born into an impoverished farming family in Saga prefecture in 1885, and was adopted into the family of a local rice merchant. He was a graduate of the 32nd class of the Imperial Japanese Naval Academy in 1904, ranking 12th out of...	1 Dec 1937 - 30 Aug 1939
25	Fleet Admiral	Isoroku Yamamoto Isoroku Yamamoto was a Japanese Naval Marshal General and the commander-in-chief of the Combined Fleet during World War II, a graduate of the Imperial Japanese Naval Academy and a student of Harvard University ....	30 Aug 1939 - 11 Aug 1941
26	Admiral	Shiro Takasu Shirō Takasu Admiral was a career naval officer in the Imperial Japanese Navy during World War II.-Biography:Takasu was a native of Sakuragawa Village, , and graduated from the 35th class of the Imperial Japanese Naval Academy, where his classmates included future admirals Nobutake Kondō and Naokuni Nomura...	11 Aug 1941 - 14 Jul 1942
27	Vice Admiral	Mizumi Shimizu	14 Jul 1942 - 20 Oct 1943
28	Admiral	Chuichi Nagumo Chuichi Nagumo was a Japanese admiral in the Imperial Japanese Navy during World War II and one time commander of the Kido Butai . He committed suicide during the Battle of Saipan.-Early life:...	20 Oct 1943 - 25 Feb 1944

Chief of Staff

	Rank	Name	Date
1	Fleet Admiral	Baron Hayao Shimamura Shimamura Hayao Baron was a Japanese admiral during the First Sino-Japanese and Russo-Japanese Wars as well as one of the first prominent staff officers and naval strategists of the early Imperial Japanese Navy.-Biography:...	28 Dec 1903 - 12 Jan 1905
2	Fleet Admiral	Viscount Tomosaburō Katō Kato Tomosaburo Viscount was a career officer in the Imperial Japanese Navy, cabinet minister, and Prime Minister of Japan from 12 June 1922 to 24 August 1923.-Biography:...	12 Jan 1905 - 20 Dec 1905
3	Admiral	Koichi Fujii	20 Dec 1905 - 22 Nov 1906
4	Fleet Admiral	Baron Gentaro Yamashita	22 Nov 1906 - 10 Dec 1908
5	Admiral	Takeshi Takarabe	10 Dec 1908 - 1 Dec 1909
6	Admiral	Kaneo Nomaguchi	1 Dec 1909 - 11 Mar 1911
7	Vice Admiral	Saneyuki Akiyama	11 Mar 1911 - 1 Dec 1912
8	Admiral	Isamu Takeshita Isamu Takeshita was an admiral in the Imperial Japanese Navy. He was also a diplomat whose accomplishments included helping end the Russo-Japanese War favorably for Japan and obtaining former German possessions in the Pacific for Japan following World War I...	1 Dec 1912 - 24 May 1913
x		position vacant	24 May 1913 - 1 Dec 1913
9	Vice Admiral	Tetsutaro Sato	1 Dec 1913 - 17 Apr 1914
10	Vice Admiral	Kazuyoshi Yamaji	17 Apr 1914 - 1 Dec 1914
11	Vice Admiral	Shibakichi Yamanaka	1 Dec 1914 - 13 Dec 1915
12	Vice Admiral	Saburo Horiuchi	13 Dec 1915 - 1 Dec 1917
13	Vice Admiral	Hanroku Saito	1 Dec 1917 - 1 Dec 1918
14	Vice Admiral	Kajishiro Funakoshi	1 Dec 1918 - 1 Dec 1919
15	Vice Admiral	Hansaku Yoshioka	1 Dec 1919 - 1 Dec 1921
16	Vice Admiral	Kumazo Shirane	1 Dec 1921 - 1 Dec 1923
17	Rear Admiral	Bekinari Kabayama	1 Dec 1923 - 10 Nov 1924
18	Vice Admiral	Kanjiro Hara	10 Nov 1924 - 1 Dec 1925
19	Vice Admiral	Naotaro Ominato	1 Dec 1925 - 1 Nov 1926
20	Admiral	Sankichi Takahashi Sankichi Takahashi was an Admiral of the Imperial Japanese Navy. After the Washington Naval Treaty of 1922 Takahashi, an important figure of IJN's Fleet Faction, made a swift career, from commander of an obsolete cruiser in 1923 to commander of the Combined Fleet in 1934...	1 Nov 1926 - 1 Dec 1927
21	Vice Admiral	Eijiro Hamano	1 Dec 1927 - 10 Dec 1928
22	Vice Admiral	Ken Terajima	10 Dec 1928 - 30 Oct 1929
23	Admiral	Koichi Shiozawa Koichi Shiozawa -External links:* - Notes :...	30 Oct 1929 - 1 Dec 1930
24	Admiral	Shigetarō Shimada Shigetaro Shimada was an admiral in the Imperial Japanese Navy during World War II. He also served as Navy Minister-Biography:A native of Tokyo, Shimada graduated from the 32nd class of the Imperial Japanese Naval Academy in 1904...	1 Dec 1930 - 1 Dec 1931
25	Admiral	Zengo Yoshida Zengo Yoshida was an admiral in the Imperial Japanese Navy.-Biography:Yoshida was born into an impoverished farming family in Saga prefecture in 1885, and was adopted into the family of a local rice merchant. He was a graduate of the 32nd class of the Imperial Japanese Naval Academy in 1904, ranking 12th out of...	1 Dec 1931 - 15 Sep 1933
26	Admiral	Soemu Toyoda	15 Sep 1933 - 15 Mar 1935
27	Admiral	Nobutake Kondō	15 Mar 1935 - 15 Nov 1935
28	Admiral	Naokuni Nomura Naokuni Nomura was an admiral in the Imperial Japanese Navy, and briefly served as Navy Minister in the 1940s.-Biography:Nomura was born in Hioki, Kagoshima prefecture. He graduated from the 35th class of the Imperial Japanese Naval Academy, ranked 43rd out of 172 cadets. He served his midshipman tour on the...	15 Nov 1935 - 16 Nov 1936
29	Rear Admiral	Yasutaro Iwashita	16 Nov 1936 - 18 Feb 1937
30	Vice Admiral	Jisaburo Ozawa Jisaburo Ozawa was an admiral in the Imperial Japanese Navy during World War II. He was the last Commander-in-Chief of Combined Fleet. Many military historians regard Ozawa as one of the most capable Japanese flag officers.-Biography:...	18 Feb 1937 - 15 Nov 1937
31	Vice Admiral	Ibo Takahashi Ibo Takahashi - Books :...	15 Nov 1937 - 5 Nov 1939
32	Vice Admiral	Shigeru Fukudome Shigeru Fukudome - Notes :...	5 Nov 1939 - 10 Apr 1941
33	Admiral	Seiichi Ito Seiichi Ito was an admiral in the Imperial Japanese Navy and commander of the battleship on its final mission towards the end of World War II.-Early career:...	10 Apr 1941 - 11 Aug 1941
34	Vice Admiral	Kengo Kobayashi	11 Aug 1941 - 6 Jan 1943
35	Vice Admiral	Gihachi Takayanagi	6 Jan 1943 - 25 Feb 1944