South Sakhalin, which was once part of Japan as Karafuto Prefecture, had indigenous populations of Nivkhs and Uilta (Orok). Like the Karafuto Koreans but unlike the Ainu, they were thus not included in the evacuation of Japanese nationals after the Soviet invasion in 1945. Some Nivkhs and Uilta who served in the Imperial Japanese Army were held in Soviet work camps; after court cases in the late 1950s and 1960s, they were recognised as Japanese nationals and thus permitted to migrate to Japan. Most settled around Abashiri, Hokkaidō. The was founded to fight for Uilta rights and the preservation of Uilta traditions in 1975 by Dahinien Gendānu.