The Imperial Japanese Army was the official ground-based armed force of the Empire of Japan from 1868 to 1945. It was controlled by the Imperial Japanese Army General Staff Office and the Ministry of the Army, both of which were nominally subordinate to the Emperor of Japan as supreme commander of the army and the Imperial Japanese Navy. Later an Inspectorate General of Aviation became the third agency with oversight of the army. During wartime or national emergencies, the nominal command functions of the emperor would be centralized in an Imperial General Headquarters (IGHQ), an ad hoc body consisting of the chief and vice chief of the Army General Staff, the Minister of the Army, the chief and vice chief of the Naval General Staff, the Inspector General of Aviation, and the Inspector General of Military Training.