The Mongolian Revolution of 1921 was a military and political event by which Mongolian revolutionaries, with the assistance of the Soviet Red Army, expelled Russian White Guards from the country, and founded the Mongolian People's Republic in 1924. Although nominally independent, the Mongolian People's Republic was a satellite state of the Soviet Union until the third Mongolian revolution in January 1990. The revolution also ended the Chinese Beiyang government's occupation of Mongolia, which begun in 1919. The official Mongolian name of the revolution is "People's Revolution of 1921" or simply "People's Revolution"