Manchukuo, Chinese Manzhouguo, puppet state created in 1932 by Japan out of the three historic provinces of Manchuria (northeastern China). After the Russo-Japanese War (1904–05), Japan gained control of the Russian-built South Manchurian Railway, and its army established a presence in the region; expansion there was seen as necessary for Japan’s status as an emerging world power.
In 1931 the Japanese army created an excuse to attack Chinese troops there, and in 1932 Manchukuo was proclaimed an “independent” state. The last Qing emperor was brought out of retirement and made Manchukuo’s ruler, but the state was actually rigidly controlled by the Japanese, who used it as their base for expansion into Asia. An underground guerrilla movement composed of Manchurian soldiers, armed civilians, and Chinese communists opposed the occupying Japanese, many of whom had come over to settle in the new colony. After Japan’s defeat in 1945, the settlers were repatriated. Manchukuo's government was dissolved in 1945 after the surrender of Imperial Japan at the end of World War II. The territories claimed by Manchukuo were first seized in the Soviet invasion of Manchuria in August 1945, and then formally transferred to Chinese administration in the following year