The Soviet Union, officially the Union of Soviet Socialist Republics, was a 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. 
Founded: 30 December 1922
Area: 22.4 million km²
Date dissolved: 26 December 1991
Currency: Soviet ruble