Imperial Japanese Army General Staff Office
The Army Ministry (陸軍省 Rikugunshō?) was created in April 1872, along with the Navy Ministry, to replace the Ministry of Military Affairs (Hyōbushō) of the early Meiji government. Initially, the Army Ministry was in charge of both administration and operational command of the Imperial Japanese Army; however, from December 1878, the Imperial Army General Staff Office took over all operational control of the Army, leaving the Army Ministry only with administrative functions. The Imperial Army General Staff was thus responsible for the preparation of war plans; the military training and employment of combined arms; military intelligence; the direction of troop maneuvers; troop deployments; and the compilation of field service military regulations, military histories, and cartography.
The Chief of the Army General Staff was the senior ranking uniformed officer in the Imperial Japanese Army and enjoyed, along with the War Minister, the Navy Minister, and the Chief of the Navy General Staff, direct access to the Emperor. In wartime, the Imperial Army General Staff formed part of the army section of the Imperial General Headquarters, an ad hoc body under the supervision of the emperor created to assist in coordinating overall command.
Following the overthrow of the Tokugawa shogunate in 1867 and the "restoration" of direct imperial rule, the leaders of the new Meiji government sought to reduce Japan's vulnerability to Western imperialism by systematically emulating the technological, governing, social, and military practices of the European great powers. Initially, under Ōmura Masujirō and his newly created Ministry of the Military Affairs (Hyōbu-shō), the Japanese military was patterned after that of Napoleonic France. However, the stunning victory of Prussia and the other members of the North German Confederation in the 1870-1871 Franco-Prussian War convinced the Meiji oligarchs of the superiority of the Prussian military model and in February 1872, Yamagata Aritomo and Oyama Iwao proposed that the Japanese military be remodeled along Prussian lines. In December 1878, at the urging of Katsura Taro, who had formerly served as a military attaché to Prussia, the Meiji government fully adopted the Prussian/German general staff system (Großer Generalstab) which included the independence of the military from civilian organs of government, thus ensuring that the military would stay above political party maneuvering, and would be loyal directly to the emperor rather than to a Prime Minister who might attempt to usurp the emperor's authority.
The administrative and operational functions of the army were divided between two agencies. A reorganized Ministry of War served as the administrative, supply, and mobilization agency of the army, and an independent Army General Staff had responsibility for strategic planning and command functions. The Chief of the Army General Staff, with direct access to the emperor could operate independently of the civilian government. This complete independence of the military from civilian oversight was codified in the 1889 Meiji Constitution which designated that the Army and Navy were directly under the personal command of the emperor, and not under the civilian leadership or Cabinet.
Yamagata became the first chief of the Army General Staff in 1878. Thanks to Yamagata's influence, the Chief of the Army General Staff became far more powerful than the War Minister. Furthermore, a 1900 imperial ordinance (Military Ministers to be Active-Duty Officers Law (軍部大臣現役武官制 Gumbu daijin gen'eki bukan sei?)) decreed that the two service ministers had to be chosen from among the generals or lieutenant generals (admirals or vice admirals) on the active duty roster. By ordering the incumbent War Minister to resign or by ordering generals to refuse an appointment as War Minister, the Chief of the General Staff could effectively force the resignation of the cabinet or forestall the formation of a new one.
Of the seventeen officers who served as Chief of the Army General Staff between 1879 and 1945, three were princes of the imperial blood (Prince Arisugawa Taruhito, Prince Komatsu Akihito, and Prince Kan'in Kotohito) and thus enjoyed great prestige by virtue of their ties to the emperor.
The American Occupation authorities abolished the Imperial Army General Staff in September 1945.
The Organization of the Army General Staff Office underwent a number of changes during its history. Immediately before the start of the Pacific War, it was divided into four operational bureaus and a number of supporting organs:
Chief of the Army General Staff (general or Field Marshal)
Vice Chief of the Army General Staff (lieutenant general)
- General Affairs (personnel, accounting, medical, mobilization planning) 
- G-1 (Operations)
- Strategy and Tactics Department
- Land Survey Department
- G-2 (Intelligence)
- Russia Department
- Europe and North America Department
- China Department
- Others Department
- G-3 (Transport & Communications)
- G-4 (Historical and Maps) 
- G-5 (Fortifications) [from Jan 1889-Dec 1908]
- General Staff College
Chiefs of the Army General Staff
Note: The given rank for each person is the rank the person held at last, not the rank the person held at the time of their post as Chief of the Army General Staff. For example, the rank of Field Marshal existed only 1872/3 and from 1898 on.
|1||24 December 1878 – 4 September 1882||Field Marshal Count Yamagata Aritomo|
|2||4 September 1882 – 13 February 1884||Field Marshal Oyama Iwao|
|3||13 February 1884 – 22 December 1885||Field Marshal Marquis Yamagata Aritomo|
|4||22 December 1885 – 14 May 1888||General Prince Arisugawa Taruhito|
|5||14 May 1888 – 9 March 1889||Lieutenant General Ozawa Takeo|
|6||9 March 1889 – 15 January 1895||General Prince Arisugawa Taruhito|
|7||26 January 1895 – 20 January 1898||Field Marshal Prince Komatsu Akihito|
|8||20 January 1898 – 11 May 1899||General Kawakami Soroku|
|9||16 May 1899 – 20 June 1904||Field Marshal Prince Ōyama Iwao|
|10||20 June 1904 – 20 December 1905||Field Marshal Prince Yamagata Aritomo|
|11||20 December 1905 – 11 April 1906||Field Marshal Prince Ōyama Iwao|
|12||11 April 1906 – 30 July 1906||General Kodama Gentarō|
|13||30 July 1906 – 20 January 1912||Field Marshal Baron Oku Yasukata|
|14||19 January 1912 – 17 December 1915||Field Marshal Hasegawa Yoshimichi|
|15||17 December 1915 – 17 March 1923||Field Marshal Uehara Yusaku|
|16||17 March 1923 – 2 March 1926||General Kawai Misao|
|17||2 March 1926 – 19 February 1930||General Suzuki Soroku|
|18||19 February 1930 – 23 December 1931||General Kanaya Hanzo|
|19||23 December 1931 – 3 October 1940||Field Marshal Prince Kan'in Kotohito|
|20||3 October 1940 – 21 February 1944||Field Marshal Sugiyama Hajime|
|21||21 February 1944 – 18 July 1944||General Hideki Tōjō|
|22||18 July 1944 - Sep 1945||General Yoshijirō Umezu|
Vice Chiefs of the General Staff
|1||5 December 1878 – 16 October 1879||Field Marshal Ōyama Iwao|
|x||16 October 1879 – 6 February 1882||Post not filled|
|2||6 February 1882 – 21 May 1885||Lieutenant General Soga Sukenori|
|3||21 May 1885 – 16 March 1886||General Kawakami Soroku|
|4||16 March 1886 – 26 July 1886||Lieutenant General Soga Sukenori|
|5||26 July 1886 – 12 May 1888||Lieutenant General Ozawa Takeo|
|x||12 May 1888 – 9 March 1889||Post not filled|
|6||9 March 1889 – 20 January 1898||General Kawakami Soroku|
|x||20 January 1898 – 26 August 1898||Post not filled|
|7||26 August 1898 – 25 April 1900||General Osako Hisatoshi|
|8||25 April 1900 – 27 March 1902||Field Marshal Terauchi Masatake|
|9||17 April 1902 – 1 October 1903||Major General Tamura Iyozu|
|10||2 October 1903 – 12 October 1903||General Fukushima Sei|
|11||12 October 1903 – 11 April 1906||General Kodama Gentaro|
|12||16 April 1906 – 25 April 1912||General Fukushima Sei|
|13||25 April 1912 – 17 April 1914||Lieutenant General Oshima Ken'ichi|
|14||17 April 1914 – 4 October 1915||General Akashi Motojiro|
|15||4 October 1915 – 10 October 1918||General Tanaka Giichi|
|16||10 October 1918 – 5 May 1921||General Fukuda Masataro|
|17||5 May 1921 – 24 November 1922||General Kikuchi Shinnosuke|
|18||24 November 1922 – 1 May 1925||Field Marshal Nobuyoshi Mutō|
|19||1 May 1925 – 5 March 1927||General Kanaya Hanzo|
|20||5 March 1927 – 1 August 1929||General Jirō Minami|
|21||1 August 1929 – 22 December 1930||Lieutenant General Okamoto Renichiro|
|22||22 December 1930 – 9 January 1932||Lieutenant General Ninomiya Osamu|
|23||9 January 1932 – 19 June 1933||Lieutenant General Masaki Jinzaburō|
|24||19 June 1933 – 1 August 1934||General Ueda Kenkichi|
|25||1 August 1934 – 23 March 1936||Lieutenant General Sugiyama Hajime|
|26||23 March 1936 – 1 March 1937||General Nishio Juzo|
|27||1 March 1937 – 14 August 1937||Lieutenant General Imai Kiyoshi|
|28||14 August 1937 – 10 December 1938||General Tada Hayao|
|29||10 December 1938 – 2 October 1939||Lieutenant General Nakajima Tetsuzo|
|30||2 October 1939 – 15 November 1940||Lieutenant General Sawada Shigeru|
|31||15 November 1940 – 6 November 1941||General Tsukada Osamau|
|32||6 November 1941 – 8 April 1943||Lieutenant General Tanabe Moritake|
|33||8 April 1943 – 21 February 1944||Lieutenant General Hata Hikosaburo|
|34||21 February 1944 – 7 April 1944||Lieutenant General Ushiroku Jun|
|35||7 April 1945 - Sep 1945||Lieutenant General Torashirō Kawabe|
- U.S. War Department, Handbook of Japanese Military Forces, TM-E 30-480 (1945; Baton Rouge and London: Louisiana State University Press, 1991, reprint).
- Hayashi, Saburo; Cox, Alvin D (1959). Kogun: The Japanese Army in the Pacific War. Quantico, Virginia: The Marine Corps Association.
- Shin'ichi Kitaoka, "Army as Bureaucracy: Japanese Militarism Revisited", Journal of Military History, special issue 57 (October 1993): 67-83.
- Edgerton, Robert B. (1999). Warriors of the Rising Sun: A History of the Japanese Military. Westview Press. ISBN 0-8133-3600-7.
- Harries, Meirion (1994). Soldiers of the Sun: The Rise and Fall of the Imperial Japanese Army. Random House. ISBN 0-679-75303-6.
- Post created 16 January 1899. Responsible for general affairs, personnel affairs, accounting, war organization and mobilization planning. Post abolished 15 October 1943 and responsibilities taken over by the General Affairs Section subordinated directly to the Vice Chief of the General Staff.
- Responsible for cartography, military history matters, translation and archives. Post abolished 15 October 1943 and responsibilities transferred to the Second Bureau