苏联, or the Soviet Union, was a socialist state that existed from 1922 to 1991. It was a federation of multiple republics, with Russia being the largest and most influential. The government was based on the principles of Marxism-Leninism, and it aimed to create a classless society through state control of the economy and collective ownership of resources. The Soviet Union played a significant role in global politics, especially during the Cold War, when it was a major rival to the United States. It was known for its space achievements, including launching the first human, Yuri Gagarin, into space in 1961. The union dissolved in 1991, leading to the independence of its republics.