The October Revolution, officially known as the Great October Socialist Revolution under the Soviet Union, also known as the Bolshevik Coup, the Bolshevik Revolution, the October Uprising, the October Coup or Red October, was a revolution in Russia led by the Bolshevik Party of Vladimir Lenin that was instrumental in the larger Russian Revolution of 1917–1923. It was the second revolutionary change of government in Russia in 1917. It took place through an armed insurrection in Petrograd on 7 November 1917 [O.S. 25 October]. The rise of the Bolshevik and anti-Bolshevik factions was the precipitating event of the Russian Civil War.
The October Revolution followed and capitalized on the February Revolution earlier in the year. The February Revolution had overthrown the Tsarist autocracy, resulting in a provisional government. The provisional government had taken power after being proclaimed by Grand Duke Michael, Tsar Nicholas II's younger brother, who declined to take power after the Tsar stepped down. During this time, urban workers began to organize into councils wherein revolutionaries criticized the provisional government and its actions.