Ukrainian Soviet Socialist Republic
Eventually, after the creation of the Communist Party (Bolshevik) of Ukraine in Moscow, a third Ukrainian Soviet government was formed on 21 December 1919 that initiated new hostilities against Ukrainian nationalists as they lost their military support from the defeated Central Powers. Eventually, the Red Army ended up controlling much of the Ukrainian territory after the Polish-Soviet Peace of Riga. On 30 December 1922, along with the Russian, Byelorussian, and Transcaucasian republics, the Ukrainian SSR was one of the founding members of the Union of Soviet Socialist Republics (USSR).
Modern history of Ukraine
Polish rule over the provinces ended in September 1939, following Nazi and Soviet attack. After the Battle of Lviv, units of the Red Army entered regional capital, Lviv, and following the staged Elections to the People's Assemblies of Western Ukraine and Western Belarus, both eastern Galicia and Volhynia were annexed by the Soviet Union.