Russian Revolution of 1917

Russian Revolution of 1917, series of events in imperial Russia that culminated in 1917 with the establishment of the Soviet state that became known as the Union of Soviet Socialist Republics (USSR). The two successful revolutions of 1917 are referred to collectively as the Russian Revolution.
The first revolution overthrew the autocratic imperial monarchy. It began with a revolt on February 23 to 27, 1917, according to the Julian, or Old Style, calendar then in use in Russia. (On January 31, 1918, the Soviet government adopted the Gregorian, or New Style, calendar, which moved dates by thirteen days; therefore, in the New Style calendar the dates for the first revolution would be March 8 to 12. Events discussed in this article that occurred before January 31, 1918, are given according to the Julian calendar.)