1st Fleet
Active	28 December 1903 – 25 February 1944
Country
Branch	Imperial Japanese Navy
Commanders
Notable commanders	Heihachiro Togo Kōichi Fujii Osami Nagano Isoroku Yamamoto Chuichi Nagumo

The 1st Fleet (第一艦隊, Dai-ichi Kantai) was the main battleship fleet of the Imperial Japanese Navy.

History

First established on 28 December 1903, the IJN 1st Fleet was created during the Russo-Japanese War when the Imperial General Headquarters divided the Readiness Fleet into a mobile strike force of cruisers and destroyers to pursue the Imperial Russian Navy's Vladivostok-based cruiser squadron (the Imperial Japanese Navy's 2nd Fleet), while the remaining bulk of the Japanese fleet (the IJN 1st Fleet) continued to blockade Port Arthur in hopes of luring the battleships of the Russian Pacific Fleet out into a classic line-of-battle confrontation. The two fleets were combined into the Combined Fleet for the final Battle of Tsushima. The decisive victory of the Japanese fleet over the Imperial Russian Navy at the Battle of Tsushima validated the doctrine of the "decisive victory", or kantai kessen as stipulated by naval theorists such as Alfred Thayer Mahan and Satō Tetsutarō in the eyes of the Imperial Japanese Navy General Staff, and future naval procurement and deployment was centered on refinements of this doctrine.^[1] The Mahanian objective was to build a fleet in being, a naval force kept deliberately in strategic reserve, as secondary forces based on cruisers and destroyers waged a campaign of attrition against an approaching enemy, who would then be destroyed in a climactic final battle similar to the Battle of Tsushima.^[2][3] 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

^[4]

	Commander-in-Chief		Dates		Previous Post	Next Post	Notes
1		Vice-Admiral Tōgō Heihachirō 東郷平八郎	28 December 1903	20 December 1905	Commander-in-chief Standing Fleet	Chairman Navy General Staff	Promoted to Admiral 6 June 1904 Also Commander-in-Chief of the Combined Fleet for entire tenure.
2		Vice-Admiral Kataoka Shichirō 片岡七郎	20 December 1905	22 November 1906	Commander-in-chief 3rd Fleet	Director Naval Shipping Bureau
3		Vice-Admiral Arima Shinichi [ja] 有馬新一	22 November 1906	26 May 1908
4		Vice-Admiral Ijūin Gorō 伊集院五郎	26 May 1908	1 December 1909	Commander-in-chief 2nd Fleet	Chairman Navy General Staff	Also Commander-in-Chief of the Combined Fleet from 8 October to 20 November 1908
5		Vice-Admiral Kamimura Hikonojō 上村彦之丞	1 December 1909	1 December 1911	Commander-in-chief Yokosuka Naval District	Naval Councilor	Promoted to Admiral
6		Vice-Admiral Dewa Shigetō 出羽重遠	1 December 1911	1 December 1913	Commander-in-chief Sasebo Naval District	Naval Councilor	Promoted to Admiral
7		Vice-Admiral Katō Tomosaburō 加藤友三郎	1 December 1913	10 August 1915	Commander-in-chief Sasebo Naval District	Minister of the Navy
8		Vice-Admiral Kōichi Fujii 藤井較一	10 August 1915	23 September 1915	Commander-in-chief Sasebo Naval District	Commander-in-chief Yokosuka Naval District
9		Vice-Admiral Yoshimatsu Shigetarō [ja] 吉松茂太郎	23 September 1915	1 December 1917	Commander-in-chief Kure Naval District	Naval Councilor	Promoted to Admiral Also Commander-in-Chief of the Combined Fleet 8 October to 20 November 1915, 1 September to 14 October 1916, 1 to 22 October 1917
10		Vice-Admiral Yamashita Gentarō 山下源太郎	1 December 1917	1 December 1919	Commander-in-chief Sasebo Naval District	Naval Councilor	Promoted to Admiral Also Commander-in-Chief of the Combined Fleet 1 September to 15 October 1918, 1 June to 28 October 1919
11		Admiral Yamaya Tanin 山屋他人	1 December 1919	24 August 1920	Commander-in-chief 2nd Fleet	Commander-in-chief Yokosuka Naval District	Also Commander-in-chief of the Combined Fleet from 1 May 1920
12		Admiral Tochinai Sojirō [ja] 栃内曽次郎	24 August 1920	27 July 1922	Vice-Minister of the Navy	Commander-in-chief Sasebo Naval District	Also Commander-in-chief of the Combined Fleet until 31 October 1920 and from 1 May to 31 October 1921
13		Vice-Admiral Takeshita Isamu 竹下勇	27 July 1922	27 January 1924		Commander-in-chief Kure Naval District	Promoted to Admiral 3 August 1923 Also Commander-in-chief of the Combined Fleet from 1 December 1922 Command of Combined Fleet and 1st Fleet would be unified for the next 20 years.
14		Admiral Suzuki Kantarō 鈴木貫太郎	27 January 1924	1 December 1924	Commander-in-chief Kure Naval District	Naval Councilor
15		Admiral Okada Keisuke 岡田啓介	1 December 1924	10 December 1926	Naval Councilor	Commander-in-chief Yokosuka Naval District
16		Vice-Admiral Katō Hiroharu 加藤寛治	10 December 1926	10 December 1928	Commander-in-chief Yokosuka Naval District	Naval Councilor	Promoted to Admiral 1 April 1927
17		Admiral Taniguchi Naomi [ja] 谷口尚真	10 December 1928	11 November 1929	Commander-in-chief Kure Naval District	Commander-in-chief Kure Naval District
18		Vice-Admiral Yamamoto Eisuke [ja] 山本英輔	11 November 1929	1 December 1931	Commander-in-chief Yokosuka Naval District	Naval Councilor	Promoted to Admiral 1 March 1931
19		Vice-Admiral Kobayashi Seizō 小林躋造	1 December 1931	15 November 1933	Vice-Minister of the Navy	Naval Councilor	Promoted to Admiral 1 April 1933
20		Vice-Admiral Suetsugu Nobumasa 末次信正	15 November 1933	15 November 1934	Commander-in-chief 2nd Fleet	Commander-in-chief Yokosuka Naval District	Promoted to Admiral 30 March 1934
21		Vice-Admiral Takahashi Sankichi 高橋三吉	15 November 1934	1 December 1936	Commander-in-chief 2nd Fleet	Naval Councilor	Promoted to Admiral 1 April 1936
22		Vice-Admiral Mitsumasa Yonai 米内光政	1 December 1936	2 February 1937	Commander-in-chief Yokosuka Naval District	Minister of the Navy
23		Admiral Nagano Osami 永野修身	2 February 1937	1 December 1937	Minister of the Navy	Naval Councilor
24		Vice-Admiral Yoshida Zengo 吉田善吾	1 December 1937	30 August 1939	Commander-in-chief 2nd Fleet	Minister of the Navy
25		Vice-Admiral Yamamoto Isoroku 山本五十六	30 August 1939	11 August 1941	Vice-Minister of the Navy	Commander-in-chief Combined Fleet	Promoted to Admiral 15 November 1940 Command of Combined Fleet and 1st Fleet separated.
26		Vice Admiral Takasu Shirō 高須四郎	11 August 1941	14 July 1942	Commander-in-chief 4th Fleet	Attendant Navy General Staff
27		Vice-Admiral Shimizu Mitsumi 清水光美	14 July 1942	20 October 1943
28		Vice-Admiral Nagumo Chūichi 南雲忠一	20 October 1943	25 February 1944	Commander-in-chief Kure Naval District

Chief of Staff^[4]