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).
Ukrainian People's Republic
The Ukrainian People's Republic, or Ukrainian National Republic (abbreviated to ', '), a predecessor of modern Ukraine, was declared on 10 June 1917 following the February Revolution in Russia. It initially formed part of the Russian Republic, but proclaimed its independence on 25 January 1918. During its short existence the republic went through several political transformations - from the socialist-leaning republic headed by the Central Council with its general secretariat to the national republic led by the Directorate and by Symon Petliura. Between April and December 1918 the Ukrainian People's Republic did not function, having been overthrown by the Ukrainian State of Pavlo Skoropadsky.
From late 1919 the UNR operated as an ally of the Second Polish Republic, but by then the state "de facto" no longer existed in Ukraine. The 18 March 1921 Treaty of Riga between the Second Polish Republic, Soviet Russia (acting also on behalf of Soviet Belarus) and of Soviet Ukraine sealed the fate of the Ukrainian People's Republic.