the Kievan Rus, but were defeated on the Pischan River by Vladimir the Great's commander Volchiy Khvost ("Wolf's Tail"). Since then, there had been no mentioning of the tribe in the chronicles. They continued living on their land, gradually assimilating with neighboring tribes and peoples and forming the Belarusian nationality. Subsequently, the lands of the Radimichs became a part of the Chernihiv and Smolensk principalities. In the Primary Chronicle, it is recorded that the Radimichs, Vyatichi, and Severians "had the same customs", all lived violent lifestyles, "burned their dead and preserved the ashes in urns set upon posts beside the highways", and they did not enter monogamous marriages but practiced polygamy, specifically polygyny, instead. The Radimichs were last mentioned in a chronicle in 1169. Origin The Tale of Bygone Years tells about the Lechites origin of the Radimichi: “…radimichi bo… from the Lechites” and “The former Radimichi from the Lechites family; before that, you are all-powerful, and pay tribute to Russia ”. These words of the chronicler had a great influence on many researchers. Medieval Polish chroniclers - Jan Długosz, Maciej Stryjkowski and others, as well as historians of the 18th and 19th centuries unconditionally recognized the Polish origin of the Radimichi. A. A. Shakhmatov tried to support the annalistic report about the Lechites origin of the Radimichi with linguistic data, referring to the fact that the Radimichi region now belongs to the territory of Belarusian language, in which there are many coincidences with the Polish. However E. F. Karsky spoke out against the theory of the Lechites origin of the Radimichi, showing the independent development of those features of the Belarusian language that bring it closer to the Polish. According to Karsky, the chronicle of the Lyash origin of the Radimichi does not indicate that they were a Lyash tribe, but that they moved to Sozh from more western regions, where they neighbored with the Lyash tribes. This opinion was also supported by Lyubor Niederle, who considered the basins of Bug and Nareva. Repeated attempts were made to determine the area from which the Radimichi came to Sozh by mapping toponymsov with the base rad-. However, such toponyms, apparently, come from anthroponyma Radim, distributed over a much larger territory than the defined regions. On the basis of hydronymics data, it was possible to establish some similarity between the hydronyms of Posozhye and the hydronyms of a small section of