Sakhalin Koreans are Russian citizens and residents of Korean descent living on Sakhalin Island, who can trace their roots to the immigrants from the Gyeongsang and Jeolla provinces of present-day South Korea during the late 1930s and early 1940s, the latter half of the Japanese colonial era.
At the time, the southern half of Sakhalin Island, then known as Karafuto Prefecture, was under the control of the Empire of Japan, whereas the northern half was part of the Soviet Union. The Japanese government both recruited and forced Korean labourers into service and shipped them to Karafuto to fill labour shortages resulting from World War II. The Red Army invaded Karafuto days before Japan's surrender; while all but a few Japanese there repatriated successfully, almost one-third of the Koreans could not secure permission to depart either to Japan or their home towns in South Korea. For the next forty years, they lived in exile. In 1985, the Japanese government offered transit rights and funding for the repatriation of the original group of Sakhalin Koreans; however, only 1,500 of them returned to South Korea in the next two decades. The vast majority of Koreans of all generations chose instead to stay on Sakhalin.

Due to differing language and immigration history, Sakhalin Koreans may or may not identify themselves as Koryo-saram. The term "Koryo-saram" may be used encompass to all Koreans in the former USSR, but typically refers to ethnic Koreans from Hamgyŏng province whose ancestors emigrated to the Russian Far East in the 19th century, and then were later deported to Central Asia. The issue of self-identification is complicated by the fact that many Sakhalin Koreans feel that Koreans from Central Asia look down on them.

History
Under Japanese colonialism
Origins
Korean immigration to Sakhalin began as early as the 1910s when the Mitsui Group began recruiting labourers from the peninsula for their mining operations. In 1920, ten years after the annexation of Korea by Japan, there were fewer than one thousand Koreans in the whole of Karafuto Prefecture, overwhelmingly male. Aside from an influx of refugees from the Maritimes, who escaped to Karafuto during the Russian Revolution of 1917, the number of Koreans in the province did not rise very rapidly; as late as the mid-1930s, there were fewer than 6,000 Koreans in Karafuto. However, as Japan's war effort picked up, the Japanese government sought to put more people on the ground in the sparsely-populated prefecture in order to ensure their control of the territory and fill the increasing demands of the coal mines and lumber yards. Recruiters turned to sourcing workers from the Korean peninsula; at one point, over 150,000 Koreans were relocated to work on the island. Of those, around 10,000 mine workers were relocated to Japan prior to the war's end; present-day Sakhalin Koreans' efforts to locate them proved futile.

The Imperial Japanese Army in Karafuto frequently used local ethnic minorities (Oroks, Nivkhs, and Ainu) to conduct intelligence-gathering activities, because, as indigenous inhabitants, their presence would not arouse suspicion on the Soviet half of the island. Ethnic Koreans could also be found on both sides of the border, but the use of Koreans as spies was not common, as the Karafuto police were wary of the support for the independence movement among Koreans. Soviet suspicion towards Korean nationalism, along with fears that the Korean community might harbour Japanese spies, led to the 1937 deportation of Koreans from Soviet-controlled northern Sakhalin and the Russian Far East, to Central Asia.
After the large scale deportation of Soviet Koreans to Central Asia, the few who were not deported continued to live in northern Sakhalin. Some 2,000 Koreans remained in northern Sakhalin as part of Soviet-Japanese oil 'concessions' (joint ventures). Contradicting the Soviet stated aim for the deportation, Japan was allowed to bring in additional workers with Soviet permission, and the facilities operated until 1943.
The origins of Sakhalin Koreans are traced to the Japanese-controlled southern half of the island.





