The event in Russia in 1917 that led to the withdrawal from World War I was the Bolshevik Revolution, also known as the October Revolution. This revolution occurred after the February Revolution, which had already dethroned Tsar Nicholas II. The Bolsheviks, led by Vladimir Lenin, seized power with the promise of "peace, land, and bread." They were fundamentally opposed to the war, arguing that it benefited the bourgeoisie at the expense of the working class. Shortly after taking control, the new Bolshevik government initiated peace negotiations with Germany, culminating in the Treaty of Brest-Litovsk in March 1918, officially ending Russia's involvement in the war.