Among the Baltic peoples are modern-day Lithuanians (including Samogitians) and Latvians (including Latgalians) — all East Balts — as well as the Old Prussians, Curonians, Sudovians, Skalvians, Yotvingians and Galindians — the West Balts — whose languages and cultures are now extinct, but made a large influence on the living branches, especially on literary Lithuanian language.

[5][better source needed] Medieval German chronicler Adam of Bremen in the latter part of the 11th century AD was the first writer to use the term "Baltic" in reference to the sea of that name.

[9][10] In 1845, Georg Heinrich Ferdinand Nesselmann proposed a distinct language group for Latvian, Lithuanian, and Old Prussian, which he termed Baltic.

The Baltic languages, especially Lithuanian, retain a number of conservative or archaic features, perhaps because the areas in which they are spoken are geographically consolidated and have low rates of immigration.

[13] Some of the major authorities on Balts, such as Kazimieras Būga, Max Vasmer, Vladimir Toporov and Oleg Trubachyov,[citation needed] in conducting etymological studies of eastern European river names, were able to identify in certain regions names of specifically Baltic provenance, which most likely indicate where the Balts lived in prehistoric times.

Its borders are approximately: from a line on the Pomeranian coast eastward to include or nearly include the present-day sites of Berlin, Warsaw, Kyiv, and Kursk, northward through Moscow to the River Berzha, westward in an irregular line to the coast of the Gulf of Riga, north of Riga.

According to one of the theories which has gained considerable traction over the years, one of the western Baltic tribes, the Galindians, Galindae, or Goliad, migrated to the area around modern-day Moscow, Russia around the fourth century AD.

In the fifth century AD parts of the eastern Baltic coast began to be settled by the ancestors of the Western Balts: Brus/Prūsa ("Old Prussians"), Sudovians/Jotvingians, Scalvians, Nadruvians, and Curonians.

[citation needed] Germanic peoples lived to the west of the Baltic homelands; by the first century AD, the Goths had stabilized their kingdom from the mouth of the Vistula, south to Dacia.

[20] In the 12th and 13th centuries, internal struggles and invasions by Ruthenians and Poles, and later the expansion of the Teutonic Order, resulted in an almost complete annihilation of the Galindians, Curonians, and Yotvingians.

[citation needed] Old Prussian was closely related to the other extinct Western Baltic languages, Curonian, Galindian and Sudovian.

[27] Unlike other parts of Europe, the hunter-gatherers of the eastern Baltic do not appear to have mixed much with Early European Farmers (EEFs) arriving from Anatolia.