Once in government, Trotsky initially held the post of Commissar for Foreign Affairs and became directly involved in the 1917-1918 Brest-Litovsk negotiations with Germany as Russia pulled out of the First World War. From March 1918 to January 1925 Trotsky headed the Red Army as People's Commissar for Military and Naval Affairs and played a vital role in the Bolshevik victory in the Russian Civil War of 1917-1922. He became one of the seven members of the first Bolshevik Politburo in 1919.