The Baltic hydronyms area stretches from the Vistula River in the west to the east of Moscow and from the Baltic Sea in the north to the south of Kyiv. Vladimir Toporov and Oleg Trubachyov (1961, 1962) studied Baltic hydronyms in Russian and Ukrainian territory. Hydronyms and archaeology analysis show that the Slavs started migrating to the Baltic areas east and north-east directions in the 6–7th centuries, before then, the Baltic and Slavic boundary was south of the Pripyat River. In the 1960s, Vladimir Toporov and Vyacheslav Ivanov made the following conclusions about the relationship between the Baltic and Slavic languages: a) Proto-Slavic formed from the peripheral-type Baltic dialects; b) the Slavic linguistic type formed later from the structural model of the Baltic languages; c) the Slavic structural model is a result of a transformation of the structural model of the Baltic languages.
The Baltic hydronyms area stretches from the Vistula River in the west to the east of Moscow and from the Baltic Sea in the north to the south of Kyiv. Vladimir Toporov and Oleg Trubachyov (1961, 1962) studied Baltic hydronyms in Russian and Ukrainian territory. Hydronyms and archaeology analysis show that the Slavs started migrating to the Baltic areas east and north-east directions in the 6–7th centuries, before then, the Baltic and Slavic boundary was south of the Pripyat River. In the 1960s, Vladimir Toporov and Vyacheslav Ivanov made the following conclusions about the relationship between the Baltic and Slavic languages: a) Proto-Slavic formed from the peripheral-type Baltic dialects; b) the Slavic linguistic type formed later from the structural model of the Baltic languages; c) the Slavic structural model is a result of a transformation of the structural model of the Baltic languages.