On 18 February 1932 Manchukuo ("The Manchurian State") was proclaimed by the Northeast Supreme Administrative Council, nominally in control of Manchuria, and was officially founded on 1 March. It was recognized by Japan on 15 September 1932 through the Japan–Manchukuo Protocol, after the assassination of Japanese Prime Minister Inukai Tsuyoshi. The city of Changchun, renamed Hsinking (), became the capital of the new entity. Chinese in Manchuria organized volunteer armies to oppose the Japanese and the new state required a war lasting several years to pacify the country.