Lithuania (ⁱ/ˌlɪθuːˈeɪniə/ or /ˌlɪθjuːˈeɪniə/; Lithuanian: Lietuva), officially the Republic of Lithuania (Lithuanian: Lietuvos Respublika) is a country in Northern Europe, the largest of the three Baltic states. It is situated along the southeastern shore of the Baltic Sea, whereby to the west lie Sweden and Denmark. It borders Latvia to the north, Belarus to the east and south, Poland to the south, and a Russian exclave (Kaliningrad Oblast) to the southwest. Lithuania has an estimated population of 3.2 million as of 2011, and its capital and largest city is Vilnius. The Lithuanians are a Baltic people, and the official language, Lithuanian, is one of only two living languages (together with Latvian) in the Baltic branch of the Indo-European language family.

For centuries, the southeastern shore of the Baltic Sea was inhabited by various Baltic tribes. In the 1230s the Lithuanian lands were united by Mindaugas, who was crowned as King of the Grand Duchy of Lithuania, the first Lithuanian state, on 6 July 1253. During the 14th century, the Grand Duchy of Lithuania was the largest country in Europe: present-day Belarus, Ukraine, and parts of Poland and Russia were territories of the Grand Duchy of Lithuania. With the Lublin Union of 1569, Lithuania and Poland formed a voluntary two-state union, the Polish–Lithuanian Commonwealth. The Commonwealth lasted more than two centuries, until neighboring countries systematically dismantled it from 1772 to 1795, with the Russian Empire annexing most of Lithuania's territory.