Japanese colonial empire

The colonial expansion of the Empire of Japan in the Western Pacific Ocean and East Asia began in 1895 with Japan's victory over the Chinese Qing dynasty in the First Sino-Japanese War. Subsequent victories over the Russian Empire (Russo-Japanese War of 1904-1905) and the German Empire (World War I) expanded Japanese rule. Taiwan came under Japanese control from 1895, Korea in 1905, Micronesia in 1914, Southern Sakhalin in 1905, several concessions in China from 1903 onwards, and the South Manchuria Railway from 1905. 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 what became known as the Greater East Asia Co-Prosperity Sphere from 1940. (The Co-Prosperity Sphere expanded to include much of China, Indo-China, Malaya, the Philippines, the East Indies, Burma and New Guinea by 1942.)

Including Mainland Japan, 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 8,510,000 km² (3,300,000 sq mi) 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 the Allies defeated Japan in 1945, colonial control from Tokyo over the far-flung territories ended. The extent of Japanese governance was restricted to the core Japanese lands (Japanese: naichi) (excepting Karafuto Prefecture, which the Soviet Union occupied in 1945 and annexed as South Sakhalin Oblast); the Nanpō and Ryūkyū Islands were returned to Japan by the United States in 1968 and 1972 respectively.

The territorial expansion of the Japanese colonial empire was marked by aggression towards other nations, with the Japanese committing numerous atrocities and war crimes, killing millions.