The issue covered in the title of the proposed paper has not yet been comprehensively, multidimensionally and modernly studied in the form of a uniform monograph, either in Polish or foreign historiography. Meanwhile, this is an important problem that undoubtedly deserves thorough study and presentation within an appropriately broad analytical framework, using universal historical analogies. In my speech, I intend to share with the audience the results of my over ten-year research on the visits of legates and envoys of the Holy See to Poland during the reign of the Piast dynasty. Since my research is aimed at a future monograph on the subject, it seems reasonable to collect in one place and in a synthetic form what has been established so far through collective effort, and then indicate which topics still require reflection and discussion. I will conclude my paper with a presentation of the project of the planned dissertation together with the research method and its questionnaire.

The year 2025 will mark exactly 1,000 years not only since the coronation of Bolesław I, but also since the coronation of Mieszko II. However there is a basic difference between them. Bolesław achieved the crown after more than 30 years of rule, as the culmination of his successful rule of the state. The crown rested on Mieszko's temple at the beginning of his reign, but only a few years later he lost it irretrievably. In the proposed paper, I intend to present once again how the royal reign of Mieszko II was seen by old Polish and foreign historiography, and also - more importantly - how many of these older perceptions are confirmed by the results of the latest research. I will also address the fundamental problem of how many times and when Mieszko made war expeditions to the territories of Saxony and which side (Poland or Germany) is responsible, in the light of the latest research on sources from the Reich, for initiating the inflaming of mutual relations at the end of the 1020s.