The Bolshevik victory established the Russian Soviet Republic, the world's first constitutionally guaranteed socialist state. The country's roots lay in the October Revolution of 1917, when the Bolsheviks, under the leadership of Vladimir Lenin, overthrew the Russian Provisional Government that had earlier replaced the House of Romanov of the Russian Empire.
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. Other major cities included Leningrad (Russian SFSR), Kiev ( Ukrainian SSR), Minsk ( Byelorussian SSR), Tashkent ( Uzbek SSR), Alma-Ata ( Kazakh SSR), and Novosibirsk (Russian SFSR). It was a one-party state governed by the Communist Party of the Soviet Union, with the city of Moscow serving as its capital within its largest and most populous republic: the Russian SFSR. 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. The Soviet Union, officially the Union of Soviet Socialist Republics ( USSR), was a country that spanned much of Eurasia from 1922 to 1991.
