Japanese colonial empire

The territorial conquests of the Empire of Japan in the Western Pacific Ocean and East Asia began in 1895 with its victory over Qing China in the First Sino-Japanese War. Subsequent victories over the Russian Empire (Russo-Japanese War) and German Empire (World War I) expanded Japanese rule to Taiwan, Korea, Micronesia, southern Sakhalin, several concessions in China, and the South Manchuria Railway. In 1931, Japan invaded Manchuria, resulting in the establishment of the puppet state of Manchukuo the following year; thereafter, Japan adopted a policy of founding and supporting puppet states in conquered regions. These conquered territories became the basis for the Greater East Asia Co-Prosperity Sphere in 1940. Including the naichi, colonies, occupied territories, and puppet states, the Empire of Japan at its apex was one of the largest empires in history. The total amount of land under Japanese sovereignty reached in 1942. By 1943, it accounted for more than 20% of the world's population at the time with 463 million people in its occupied regions and territories. After Japan was defeated by the Allies in 1945, colonial control from Tokyo over the far-flung territories ended. The extent of Japanese governance was restricted to the naichi (excepting Karafuto Prefecture, which was annexed by the Soviet Union); the Nanpō and Ryūkyū Islands were returned to Japan by the US in 1968 and 1972 respectively. The first overseas territories that Japan acquired were the islands of its surrounding seas. During the early Meiji era, Japan established control over the Nanpō, Ryukyu, and Kuril Islands; it also strengthened control of the naichi. But this effort was less an initial step toward colonial expansion than it was a reassertion of national authority over territories traditionally within the Japanese cultural sphere. At the start of the twentieth century the rate of population increase in Japan was seen as a potential problem for the Japanese government, and colonial expansion into Korea and Manchuria was seen as a possible solution.