To explain chronology and origins of cemeteries of graves in stone settings examination of complementary issues are needed: the provenience of grave furnishings and their usefulness in dating burial groups; the mutual spatial relationship of the two principal variants of Northern Masovia non-church burial grounds, i.e. with and without graves in stone settings; the chronological and settlement context relation of cemeteries with graves in stone settings from two zones of extensive occurrence, in northern Masovia and in Podlaquia. It is also essential to take into account the political events in the middle of the 11th century that have been recorded in the written sources. The grave furnishings of Northern Masovia are of generally Western Slavic character, but some objects present a foreign provenience (military paraphernalia, as well as luxury items, ornaments, clay rattles etc.) from Rus', Scandinavia and Balt cultures. Cemeteries with graves in stone settings started in both northern Masovia and Podlaquia simultaneously about the middle of the 11th century, being indirectly the effect of the new political order on the Vistula and Bug. The political changes were instigated by the allied princes of Poland and Rus', following their defeat of a common enemy in the person of the self-proclaimed ruler of Masovia, Mieclaw. Podlaquia passed then into the hands of the Kiev Rus' state and northern Masovia was returned to the Piast rulers. Varegian Rus' warriors from the east played an active role in these events. They brought the idea of graves in stone settings to the Old Masovia region.