Keywords: Early Modern Poland-Lithuania; Royal Dignity; Papal Diplomacy; Ceremonial Role.
Early modern Poland-Lithuania was particularly important for Holy See's political and the religious projects in that it was seen to constitute a "bulwark of Christianity" and the West's cultural external boundary. For this reason, the problems of discontinuity of the royal dignity and free elections became important for the papacy. This article illustrates the role of papal diplomacy in the parliamentary practice of Polish-Lithuanian "interregnums" from 1572 to 1676, in particular during key moments like the Convocation Sejm, the Election Sejm and the coronation ceremony. Its aim is not only to describe the political activity of apostolic nuncios, but also to focus on their ceremonial role. The topic is also closely connected to the question of papal neutrality and the image of a "padre comune", ideas that were constantly evolving during the early modern period.