Estonia, Latvia, and Lithuania, on the eastern coast of the Baltic Sea. Formerly Russian provinces, they became independent countries after World War I and were incorporated into the USSR as constituent republics in 1940. They became independent again in 1991. the Baltic States Estonia, Latvia, and Lithuania considered together as one group. Republics of Lithuania, Latvia, and Estonia, situated on the eastern shore of the Baltic Sea. The name has sometimes been used to include Finland and Poland. They were created as independent states in 1917 from the Baltic provinces of Russia, the city of Kovno, and part of the Polish department of Wilno (later Lithuania). With the aid of German and Allied forces, the Baltic states repelled a Bolshevik invasion in 1919. In 1940 they were forcibly occupied by the Soviet Union and incorporated as constituent republics. In 1944 Soviet troops recovered the territory overrun by German forces in 1941. The Baltic states gained independence on the breakup of the Soviet Union in 1991