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).
History of Ukrainian nationality
Meanwhile, the Red Army conquered most of the Ukrainian National Republic by the end of 1920. With the signing of the Treaty of Riga, the Bolsheviks recognised the Polish claim to Galicia and other parts of western Ukraine, while the Poles recognised Soviet claims to the rest of Ukraine. Until the Nazi-Soviet invasion of Poland in 1939, Ukraine would remain divided between Poland the newly formed Union of Soviet Socialist Republics.