Bałtyckie nazewnictwo Mazowsza

As one could expect, the greatest number of the Baltic hydronyms and toponyms are featured in the northeastern part of the Mazovia region in the area of the confluence of the entire Narew and lower Bug. These are mainly names of rivers (35), less numerous are place names (24). The majority of these names is motivated by names featured in the area of historical Prussia and Yatvingia. Moreover, some of them even have direct equivalents in that region; references to the Lithuanian language are less common. This enables us to surmise that the prehistorical Mazovia region was inhabited by West Baltic people, and the Slavic colonizers reached this area in the late prehistorical period.