The Bolshevik Revolution occurred in Russia in 1917, specifically from October 25 to November 7 according to the Julian calendar, which corresponds to November 7 to November 20 in the Gregorian calendar. This revolution, led by the Bolshevik Party under Vladimir Lenin, resulted in the overthrow of the Provisional Government that had been established after the abdication of Tsar Nicholas II in February 1917. The revolution established a communist government in Russia, marking the beginning of a new era characterized by radical social and political change. It set the stage for the eventual formation of the Soviet Union and the spread of communist ideology worldwide.