a peace agreement made on March 3rd, 1918, between Germany and its allies and Soviet Russia. (March 3, 1918) Peace treaty signed at Brest-Litovsk (now in Belarus) by the Central Powers with Soviet Russia, concluding hostilities between those countries in World War I. Russia lost the Ukraine, its Polish and Baltic territories, and Finland by signing the treaty, which was later annulled by the Armistice