The “Mari” Hypothesis in the Study of the Toponymy of the Oka and Unzha Rivers and the Western Borders of the Old Mari Toponymic Area

Referring to toponymic data, the article aims to verify the hypothesis of the western origin of the Mari people who, presumably, migrated to their present-day settlement area from the territory of Kostroma Region and the Oka River basin. The author critically examines the possibility of Mari origin of some place names in the territory in question, namely, of hydronyms ending in -ingir'. To verify the “Mari” hypothesis, the author uses the method of ethnic modelling which consists in the isolation of typical toponymic stems in present-day Mari toponymy and searching for their traces in the substrate toponymy of the studied area. The analysis leads to conclude that it is unlikely that the toponymy of the western part of Kostroma Region and the Oka River basin could be of Mari origin. The area of distribution of typical Mari place names does not display any evidence of Mari substrate or superstrate to the west of the Kerzhanets River basin. On the Western bank of the Volga, some traces of substratal Mari toponymy can be found along the banks of the Sura River as far as the city of Alatyr, however, no Mari “residue” can be found west of the Sura. The absence of Mari substrate in the toponymy of the Oka and Unzha Rivers area makes it possible to refute the hypothesis of the western origin of the Mari and their migration from the area of Gorodets and Dyakovo archaeological cultures. At the same time, the study of phonetic correspondences reflected in place names reveals evidence of close kinship of the substratal dialects of Western Kostroma Region, the low Oka and Klyazma Rivers area with the Mari (Proto-Mari) language