looks like it was started in december 1922 (SFSR), and officially ended december 1991.
The Union of Soviet Socialist Republics
Union of Soviet Socialist Republics
Union of Soviet Socialist Republics.
Union of Soviet Socialist Republics.
United Soviet Socialist Republics is the full, official name for the Soviet Union and often abbreviated USSR.
Union of Soviet Socialist Republics (USSR) also known as Soviet Union. Most of which was Russia.
1917
1922.
Union of Soviet Socialist Republics
Union of Soviet Socialist Republics
Union of Soviet Socialist Republics
There were fifteen.