The Union of Soviet Socialist Republics abbreviated to USSR or the Soviet Union is a constitutionally socialist nation which was founded in 1922, it is ruled as a Communist single party state. It is a union of 15 sub-national Soviet Republics and several space Soviets and orbital autonomous socialist zones. In practice, the Soviet Union was highly centralized until recent reforms. The largest ethnic group, the Russians, have political, cultural and economic control over the Union. However, an increasing amount of ethnic minorities are seeking greater say in their republics. The Soviet Union is the largest nation by area and the fourth largest by population.