The policy of the Holy See in Central Europe and the Balkans during the activities of Constantine and Methodius in the Moravian state and the Latin missionaries in Bulgaria

The subject of the article is the policy of the Holy See during the pontificates of Nicholas I, Hadrian II and John VIII with regard to countries in Central Europe and the Balkans. It was the result of the complex relations between the papacy and the Carolingians, the Byzantine Empire as well as the Slavic states. The Moravian rulers (Rostislav and Sviatopluk) and, Boris-Michael, the Khan of Bulgaria, used the interest of the Holy Sees diplomacy in these regions to implement their own ecclesiastical and political plans. An analysis of mutual diplomatic contacts shows more interest in Boris-Michaels state in the diplomatic activity of the papacy than in the Moravian state. The change in the policy of the Holy See took place after the fiasco of making the Bulgarian state dependent on the Church, as well as with the deterioration of relations with the East Frankish monarchy (in ecclesiastical and political matters). This contributed to the growing importance of the Moravian state in the diplomatic activities of Rome in Central Europe (the Gloria in excelsis Deo papal bull).