The Soviet Union (or more formally USSR – the Union of Soviet Socialist Republics) was established in 1922 as a federation of nationalities, which eventually came to encompass 15 major national territories, each organized as a Union-level republic (Soviet Socialist Republic or SSR).
The Soviet Union (or more formally USSR – the Union of Soviet Socialist Republics) emerged in 1922 as a union of various ethnic and national entities, which ultimately encompassed 15 major territories, each structured as a Union-level republic (Soviet Socialist Republic or SSR).