Bolshevik Russia signs the Treaty of Brest-Litovsk with the Central Powers, abandoning the Allied war effort and granting independence to its Polish and Baltic territories, the Ukraine, and Finland.
Russia's disastrous involvement in World War I was a primary factor that led to Vladimir Lenin's successful Marxist revolution in November 1917. In December 1917, Germany agreed to an armistice and peace talks with Russia, and Lenin sent Leon Trotsky to Brest-Litovsk in Belarus to negotiate a treaty. The talks broke off after Germany demanded independence for Russian holdings in Eastern Europe, and in February 1918 fighting resumed on the eastern front. With German troops advancing on St. Petersburg, Lenin authorized the signing of the Treaty of Brest-Litovsk on March 3, 1918.
German leaders hoped that the formerly Russian territories would fall under their sway, but in November 1918 an armistice ended World War I, dooming Germany to demilitarization and Allied domination. In 1919, Soviet Russia regained the Ukraine in the Russian Civil War and in 1939 seized parts of Poland, and in 1940 the Baltics, following the signing of the Nazi-Soviet nonaggression pact.