History of Lithuania
On February 16, 1918, Lithuania was re-established as a democratic state. It remained independent until the outset of World War II, when it was occupied by the Soviet Union under the terms of the Molotov–Ribbentrop Pact. Following a brief occupation by Nazi Germany after the Nazis waged war on the Soviet Union, Lithuania was again absorbed into the Soviet Union for nearly 50 years. In 1990–1991, Lithuania restored its sovereignty with the Act of the Re-Establishment of the State of Lithuania. Lithuania joined the NATO alliance in 2004 and the European Union as part of its enlargement in 2004.
Lithuania proper
Lithuania proper (, literally: "Genuine Lithuania"; ; , "Lite") refers to a region which existed within the Grand Duchy of Lithuania, and where the Lithuanian language was spoken. The primary meaning is identical to the Duchy of Lithuania, a land around which the Grand Duchy of Lithuania evolved. The territory can be traced by Catholic Christian parishes established in pagan Baltic lands of the Grand Duchy of Lithuania subsequent to the Christianization of Lithuania in 1387. They were quite distinguishable, since Ruthenian parts of the Duchy have been already baptised in an orthodox manner. The term in Latin was widely used during the Middle Ages and can be found in numerous historical maps until World War I.