Nation in eastern Europe, bounded by Lithuania and Latvia on the N, Russia on the E, the Ukraine on the S, and Poland on the W. It was formerly the Belorussian Soviet Socialist Republic of the USSR, and its capital is Minsk. East Slavic tribes colonized the region between the fifth and eighth centuries a.d., and in the next century it came under the rule of Kiev. Divided into several Belorussian principalities in the 12th century, it remained part of the then flourishing Kievan state. The destruction of that power by the Mongols in the 13th century opened the way for its conquest by Lithuania in the 14th century. Thereafter Poland and Lithuania united, with the result that when Poland was partitioned in 1772, 1793, and 1795, all of Belorussia became Russian territory. Belorussia was almost continually devastated, first by the wars of the 16th to the 18th centuries between Poland and Russia; then when Napoleon I invaded it in 1812; then in World War I; and during the Polish-Soviet war of 1919–20. In March 1918 Belorussia proclaimed its independence, but it fell under Soviet rule in 1919. After another Polish- Soviet war in 1921, Western Belorussia was given to Poland but was retaken by the USSR in World War II. During the war the region was again devastated by the German invasion. The western border was adjusted slightly in favor of Poland in 1945. In 1986, the Chernobyl atomic reactor accident contaminated much of the nation’s territory, forcing many to evacuate. In 1991, Belarus declared independence, but has continued to be much closer aligned to Russia than the other former Soviet republics. A union with Russia was proposed in 1997. Belarus continues to be the most “Soviet” of the former republics. In 2003, Belarus, Kazakhstan, Russia, and Ukraine signed an agreement to create a common economic space.