The October Revolution, also known as the Bolshevik Revolution, was the second phase of the Russian Revolution, the first having been instigated by the events around the February Revolution. It was led by Vladimir Lenin and marked the first officially communist revolution of the twentieth century, based upon the ideas of Karl Marx.
On November 7, 1917, Bolshevik leader Vladimir Lenin led his leftist revolutionaries in a nearly bloodless uprising in Petrograd, the then capital of Russia, against the ineffective Kerensky Provisional Government (Russia was still using the Julian Calendar at the time, so period references show an October 25 date). Later official accounts of the revolution from the Soviet Union would depict the events in October as being far more dramatic than they actually had been.
For the most part, the revolt in Petrograd was bloodless, with the Bolsheviks taking over major government facilities with little opposition before finally launching an assault on the Winter Palace. Official films made much later showed a huge storming of the Winter Palace and fierce fighting, but in reality the Bolshevik insurgents faced little or no opposition and were practically able to just walk into the building and take over.
The Second Congress of Soviets was occurring at the same time, and of its elected 649 delegates, 390 were Bolshevik and nearly a hundred were Left Socialist-Revolutionaries, who also supported the overthrow of the Kerensky Government. When the fall of the Winter Palace was announced, the Congress adopted a decree transferring power to the Soviets of Workers', Soldiers' and Peasants' Deputies, thus ratifying the Revolution. The transfer of power was not without disagreement. Many of the Socialist Revolutionaries believed that Lenin and the Bolsheviks had illegally seized power and they walked out before the resolution was passed. As they exited they were taunted by Leon Trotsky who told them "yes, walk out, go ahead, leave, you are entering the dust heap of society." The following day, the Soviet elected a Council of People's Commissars (Sovnarkom) as the basis of a new Soviet Government, pending the convocation of a Constituent Assembly, and passed a Decree of Peace and a Decree on Land.
The success of the October uprising ended the phase of the revolution instigated in February and transformed the Russian Revolution from liberal to socialist in character. An attempt to take over Moscow a month later was met with much more violent resistance, and the Bolsheviks did not seize full control of the city until March 1918.
The United States did not recognize the new Russian government until the 1930s. The U.S. even sent 10,000 troops to assist a Japanese invasion, as a way to speak out against the Bolshevist takeover of Russia.
The Great October Socialist Revolution was the official name for the October Revolution in the Soviet Union, used since the 10th anniversary celebration of the Revolution in 1927. Today this name is used mainly by Russian Communists.