Ukrainian Soviet Socialist Republic
The Ukrainian Soviet Socialist Republic (Ukrainian SSR or UkrSSR or UkSSR; , УРСР ; , УССР ; see "Name" section below), also known as the Soviet Ukraine, was one of the constituent republics of the Soviet Union from the Union's inception in 1922 to its breakup in 1991. The republic was governed by the Communist Party of Ukraine as a unitary one-party socialist soviet republic.
Ukrainian People's Republic
After the Bolshevik Revolution of November 1917, many governments formed in Ukraine – most notably the Ukrainian People's Republic (based in Kiev) and the Ukrainian People's Republic of Soviets (1917–1918, based in Kharkiv) and its Soviet successors. These two entities, plus the White Movement, Poland, Green armies and the Revolutionary Insurrectionary Army of Ukraine, fought constantly with each other, which resulted in many casualties among Ukrainians fighting in a Ukrainian civil war (1917-1921) as part of the wider Russian Civil War of 1917-1922. The Soviet Union would (after the 1921 Treaty of Riga) extend control over what would ultimately become the Ukrainian Soviet Socialist Republic and (in 1922) a founding member of the Soviet Union.