The pivotal confrontation in 1917 that led to the eventual withdrawal of Russia from World War I was the Bolshevik Revolution. The revolution, which unfolded in October (November in the Gregorian calendar), saw the Bolsheviks, led by Vladimir Lenin, seize power from the Provisional Government. The new Bolshevik regime was opposed to the war, viewing it as imperialist and burdensome for the Russian populace. Subsequently, they signed the Treaty of Brest-Litovsk with Germany in March 1918, officially withdrawing Russia from the war and ceding large territories in Eastern Europe, which allowed the Central Powers to focus on the Western Front.