ソビエト連邦, or the Soviet Union, was a socialist state that existed from 1922 to 1991. It was made up of multiple republics, with ロシア being the largest and most influential. The government was based on the principles of マルクス主義 and レーニン主義, promoting a planned economy and state ownership of resources. The Soviet Union played a significant role in global events, particularly during the 冷戦 era, when it was a major rival to the アメリカ合衆国. It was known for its achievements in space exploration, including launching the first human, ユーリ・ガガーリン, into space in 1961. The union dissolved in 1991, leading to the independence of its republics.