The Bolsheviks took power in Russia through the October Revolution and soon signed the Armistice of Erzincan to stop the combat in Turkish Armenia. Russian forces abandoned their positions and left the area under weak Armenian control. The Bolsheviks set up the Transcaucasian Commissariat in the Caucasus. The Treaty of Brest-Litovsk was signed on 3 March 1918 and the Ottoman army started to regain the lost territories, taking over Kars by 25 April. Russia signed the Treaty of Brest-Litovsk with the Ottoman Empire and by April 1918 the Transcaucasian Federation proclaimed its independence from Russia. This fragile federation of Armenia, Georgia and Azerbaijan collapsed when the Turks invaded the Caucasus region. The Armenian units defeated the Turks at the Battle of Sardarabad, just 40 kilometers away from Armenia's future capital Yerevan, preventing the complete destruction of the Armenian nation.