ENThis article presents a concise overview of research on the Northern Kresy variety of the Polish language (polszczyzna północnokresowa). There is extensive literature on the subject, but there is still no comprehensive bibliography which would accurately document the rich legacy of several generations of researchers working in this field of study. Northern Kresy Polish is a variety of the Polish language which formed in the historical Slavic-Baltic borderland, mainly as a result of the processes of Polonisation of the local population. Contacts between various ethnolinguistic communities resulted in significant social and territorial diversity of Northern Kresy Polish in the seventeenth and eighteenth centuries. The diferences between its variants consist mainly in the frequency of features and the scale of infuence of local languages and dialects on the grammatical system and vocabulary of Polish. Nevertheless, it is possible to identify a set of constitutive features of Northern Kresy Polish which function throughout its entire geographical area. Currently, Northern Kresy Polish is defined as the language of the Polish minority in Belarus, Lithuania and Latvia. It is apparent that the Polish language in all of these countries is in decline. Keywords: Northern Kresy Polish; origins; territorial and social diferentiation; state of research. [From the publication]