In this article, the author focuses on the analysis of Mieczysław Józefczyk’s book: Kościół i społeczeństwo w Prusach krzyżackich. Teksty źródłowe do dziejów chrześcijaństwa w Pomezanii i Pogezanii (Church and Society in Teutonic Order Prussia. The Textual Sources for the History of Christianity in Pomesania and Pogesania), published by the Warmińskie Wydawnictwo Diecezjalne in Elbląg in 2017. A detailed criticism of the author’s methodology of the book is presented, with the correction of many errors related to the historical geography of medieval Prussia, medieval chronology and philology. The book, in which we find Polish translations of 548 documents, has numerous mistakes that distort the picture of the settlement in the area of Pomesania, Pogesania and Warmia. This article also highlights numerous errors in the translations from Latin and German. The medieval terminology used in the book is also corrected. There were many errors relating to the methodology of working with a medieval source. Translated by Aleksander Pluskowsk