The Ministry of Greater East Asia was established on 1 November 1942 under the administration of Prime MinisterHideki Tōjō, by absorbing the earlier Ministry of Colonial Affairs (拓務省, Takumushō) and merging it with the East Asia Department and South Pacific Department of the Foreign Ministry and the East Asia Development Board (興亜院, Kōain), which looked after affairs in Japanese-occupied China.
Theoretically, the ministry had political and administrative responsibilities in a vast 4.4-million-square-kilometer (1.7-million-square-mile) area under Japanese influence (extending south 7,200 kilometers (4,500 miles) from the Aleutians to the Solomon Islands, and west 8,000 km (5,000 mi) from Wake Island to Burma and the Andamans), with perhaps a population of over 300 million inhabitants. In reality, wartime conditions meant that the ministry was little more than a paper creation. Aside from the first Minister of Greater East Asia, Kazuo Aoki, all succeeding ministers simultaneously held the portfolio of the Foreign Minister.