, also called the Army General Staff, was one of the four principal agencies charged with overseeing the
Imperial Japanese Army.

Postcard with view of Imperial General Staff Office HQ, circa 1910
Role
The 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.
Origins and development
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 () decreed that the two service ministers had to be chosen from among the
generals (or
admirals) or
lieutenant generals (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.
Organization
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)
- *Strategy and Tactics Department
- *Europe and North America Department
- G-3 (Transport & Communications)
- G-4 (Historical and Maps)
- G-5 (Fortifications) [from Jan 1889-Dec 1908]
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.
Vice Chiefs of the General Staff