Baltic claims to be the most archaic family still being spoken. It is a member of the "satem" group of Indo-European languages.

Old Prussian belongs to the West Baltic branch whereas Lithuanian, Lettish (Latvian) and the dialects Curonian, Semigallian and Selonian form the East Baltic branch.

Common East Baltic disintegrated rather recently. Lithuanian and Lettish reached their modern forms in the 19th and 20th centuries.

Galindian, an even more primitive Baltic language, was spoken in White Russian before the East Slavonic expansion in CE 500-600. It is recognised in place names.