In the history of studies regarding the beginnings of Lithuania and rule of Mindaugas that have already been extensively conducted for 200 years, the works by Polish historians – J. Latkowski, W. Kamieniecki, H. Łowmiański, and H. Paszkiewicz – hold a significant position. The discussion of international historians around the concept of the genesis of Lithuania and opinions on Mindaugas and his actions shaped the long-term perception of the beginnings of Lithuania and its Christianization. The polemic, disrupted by the outbreak of the Second World War, was brought back later on, but with a lower impact and less prominent participation of Polish researchers. In Polish historiography, the neglected issue of the genesis of Lithuania and the beginnings of its Christianization, on a scientific level, was restored by K. Stopka (the 1st attempt of Christianization; 1987) and K. Pietkiewicz (the beginnings of statehood; 2010). At that time, extensive studies were carried out over the said subjects by medieval researcher E. Gudavičius who concluded his work in 1998 with a contemporary monograph titled Mindaugas. However, neither the Lithuanian researcher did refer in any way to the scientifically valuable studies by K. Stopka with regard to the baptism of Mindaugas, nor K. Pietkiewicz made a reference to the monograph by Gudavičius, although he is most certainly familiar with it. Pietkiewicz’s work is not the only example. Thus, it is worthwhile to confront the perception of the genesis of Lithuanian monarchy in the contemporary Polish historiography with the views on the same subject among Lithuanian researchers.