Revolution Day commemorates the October Revolution of 1917, when the Bolsheviks overthrew the Russian government by seizing power in Petrograd (formerly St. Petersburg, later named Leningrad, and in 1991, after the collapse of the Communist Party, renamed St. Petersburg). The coup took place on November 7 (October 25 on the Julian calendar) and, through the years, was celebrated as a national holiday marking the start of the Soviet regime. All of this ended in 1991 with the Soviet Union’s disintegration. Discuss
Source: The Free Dictionary