The
Soviet Union, officially the
Union of Soviet Socialist Republics (
USSR), was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national republics; in practice, both its government and its economy were highly centralized until its final years. It was a one-party state governed by the Communist Party of the Soviet Union, with the city of Moscow serving as its capital as well as that of its largest and most populous republic: the Russian SFSR. Other major cities included Leningrad, Kiev, Minsk, Tashkent, Alma-Ata, and Novosibirsk. It was the largest country in the world, covering over 22,402,200 square kilometres (8,649,500 sq mi) and spanning eleven time zones.