Unknown letters of Antonio Possevino from the collection of historian N. P. Likhachev.

In the article, the author analyzes unknown letters of the papal legate Antonio Possevino (1534-1611) from the collection of the historian - source scholar N.P. Likhachev (1862-1936), which were discovered by the researcher during the study of Russian-Polish documents in the Scientific and Historical Archive of the St. Petersburg Institute of History of the Russian Academy of Sciences on January 25, 2024. Antonio Possevino met several times with Ivan the Terrible, trying to convince the ruler to convert from Orthodoxy to Catholicism, to conclude a religious union. The diplomat acted as an intermediary between Ivan the Terrible, Stefan Batory and the Pope. However, for a number of reasons, the mission of the papal envoy was unsuccessful. And although Muscovy lost in the Livonian War, it did not change its original faith. The author used various research methods: analysis, synthesis, adhered to a systematic approach and scientific objectivity, used textual analysis, contextual analysis. Textual analysis helped to understand the worldview of Possevino The letters of the papal envoy presented in the article are introduced into scientific circulation for the first time and were previously not known. The letters help change perceptions of Possevino and his mission, reinterpreting his role in history. The analysis of the sources that we introduce into scientific circulation contributes to the understanding of diplomatic relations between Muscovy and the West in the 16th century. It becomes clear that Muscovy for the papal envoy is a country that is interesting to him. Russia did not seek to advertise its actions in Europe. Evidence of this is that European courts did not feel interest in her, and Possevino, through a familiar bishop, advertised his works. We learn the extra information about Antonio Possevino's personality. The ideological opponent of Ivan the Terrible acquires the features of a living person who is cunning, dodgy and professional. Possevino has a sincere interest (despite the fact that he is an ideological opponent of Ivan the Terrible) in Muscovy, which follows from the nature of these letters. The letters are different in content: in the first more about Posevino's attitude towards Muscovy, in the second about the private religious affairs of the papal legate.