The State Flag of the Union of Soviet Socialist Republics (Russian: Госуда́рственный флаг Сою́за Сове́тских Социалисти́ческих Респу́блик, tr. Gosudárstvenny flag Soyúza Sovétskikh Sotsialistícheskikh Respúblik), commonly known as the Soviet flag (Russian: Сове́тский флаг, tr. Sovétsky flag), was the official state flag of the Union of Soviet Socialist Republics (USSR) from 1922 to 1991. The flag's design and symbolism are derived from several sources, but emerged during the Russian Revolution. The flag is also an international symbol of the communist movement as a whole.