Duchy of Lithuania Duchy of Lithuania Duchy of Lithuania (; ) was a state-territorial formation of ethnic Lithuanians, that existed from the 13th century until 1413. Most of the time it was a constituent part and a nucleus of the Grand Duchy of Lithuania. Other alternative names of the territorial formation, used in different periods, were Aukštaitija or Land of Lithuania (13th century), Duchy of Vilnius (14th – early 15th centuries), Lithuania Propria or simply Lithuania (in a narrow sense). The formation emerged in the central and eastern part of the present-day Lithuania, known as Aukštaitija, as the Lietuva Land (). It is
Name of Lithuania original word should have no suffix. A likely candidate is "Lietā". Because many Baltic ethnonyms originated from hydronyms, linguists have searched for its origin among local hydronyms. Usually such names evolved through the following process: hydronym → toponym → ethnonym. A small river not far from Kernavė, the core area of the early Lithuanian state and a possible first capital of the would-be Grand Duchy of Lithuania, is usually credited as the source of the name. This river's original name is Lietava. As time passed, the suffix -"ava" could have changed into -"uva", as the two are from the same