<P> The Russian Revolution was a pair of revolutions in Russia in 1917 which dismantled the Tsarist autocracy and led to the rise of the Soviet Union . The Russian Empire collapsed with the abdication of Emperor Nicholas II and the old regime was replaced by a provisional government during the first revolution of February 1917 (March in the Gregorian calendar; the older Julian calendar was in use in Russia at the time). Alongside it arose grassroots community assemblies (called' soviets') which contended for authority . In the second revolution that October, the Provisional Government was toppled and all power was given to the soviets . </P> <P> The February Revolution (March 1917) was a revolution focused around Petrograd (now Saint Petersburg), the capital of Russia at that time . In the chaos, members of the Imperial parliament (the Duma) assumed control of the country, forming the Russian Provisional Government which was heavily dominated by the interests of large capitalists and the noble aristocracy . The army leadership felt they did not have the means to suppress the revolution, resulting in Nicholas's abdication . The soviets, which were dominated by soldiers and the urban industrial working class, initially permitted the Provisional Government to rule, but insisted on a prerogative to influence the government and control various militias . The February Revolution took place in the context of heavy military setbacks during the First World War (1914--18), which left much of the Russian Army in a state of mutiny . </P> <P> A period of dual power ensued, during which the Provisional Government held state power while the national network of soviets, led by socialists, had the allegiance of the lower classes and, increasingly, the left - leaning urban middle class . During this chaotic period there were frequent mutinies, protests and many strikes . Many socialist political organizations were engaged in daily struggle and vied for influence within the Duma and the soviets, central among which were the Bolsheviks ("Ones of the Majority") led by Vladimir Lenin who campaigned for an immediate end to the war, land to the peasants, and bread to the workers . When the Provisional Government chose to continue fighting the war with Germany, the Bolsheviks and other socialist factions were able to exploit virtually universal disdain towards the war effort as justification to advance the revolution further . The Bolsheviks turned workers' militias under their control into the Red Guards (later the Red Army) over which they exerted substantial control . </P> <P> In the October Revolution (November in the Gregorian calendar), the Bolsheviks led an armed insurrection by workers and soldiers in Petrograd that successfully overthrew the Provisional Government, transferring all its authority to the soviets with the capital being relocated to Moscow shortly thereafter . The Bolsheviks had secured a strong base of support within the soviets and, as the now supreme governing party, established a federal government dedicated to reorganizing the former empire into the world's first socialist republic, practicing soviet democracy on a national and international scale . The promise to end Russia's participation in the First World War was honored promptly with the Bolshevik leaders signing the Treaty of Brest - Litovsk with Germany in March 1918 . To further secure the new state, the Cheka was established which functioned as a revolutionary security service that sought to weed out and punish those considered to be "enemies of the people" in campaigns consciously modeled on similar events during the French Revolution . </P>

Who was the leader of the bolsheviks in 1917 during the november revolution