This article is devoted to an analysis of burials with weaponry from the Ostriv graveyard near the River Ros’, about 100 kilometres to the south of Kyiv in the Middle Dnieper area, excavated during 2017 and 2018. Weapons (axes, pila, sword pommels) were discovered in 11 burials, representing approximately 20% of the total number of burials, and about 60% of all male burials investigated in the graveyard. An analysis of the material from the graveyard (weapons and jewellery) refers burials to West Balt migrants: Old Prussians, Curonians and Skalvians. They probably protected hill-forts of Kyivan Rus’ in the Ros’ region. The archaeological finds were supported by historical sources: chronicles of Kyivan Rusʼ. They evidence about the activities of Yaroslav the Wise aimed at reinforcing the southern borders of Kyivan Rus’. But it is hard to say exactly when Yaroslav relocated West Balts to the region of the River Ros’. Nevertheless, according to written sources and archaeological material, it could be dated from 1030 to the middle of the 11th century.