During the later years of China under the ROC, which was engaged against the Chinese Communists in the context of the Chinese Civil War, the Soviet Union under leader Joseph Stalin invaded Xinjiang and assisted a local rebellion at Ili (Yining City). The rebellion led to the establishment of the Second East Turkistan Republic (1944–1949), which existed in three northern districts (Ili, Tarbaghatai, Altai) of Xinjiang with secret aid from the Soviet Union. After emerging victorious at the conclusion of the Chinese Civil War in 1949, the People's Liberation Army annexed Xinjiang from the ROC and the Second East Turkestan Republic.