Servus post Deum beati Petri: Предговорът на Анастасий Библиотекар към Осмия вселенски събор – нов превод и интерпретация на отношенията между княз Борис-Михаил и Римската църква

<jats:p>This study offers an annotated translation and interpretative reading of the Praefatio by Anastasius Bibliothecarius to the decrees of the Eighth Ecumenical Council (869–870), focusing on its value as a Latin source for the Roman understanding of canonical legitimacy in Bulgaria's choice of ecclesiastical jurisdiction between Rome and Constantinople. Rather than treating the text solely as a polemical document of the Photian Schism, the article approaches it as a carefully constructed conceptual narrative that articulates a distinct Western understanding of ecclesiastical order and authority. Special attention is devoted to the language and rhetoric of submission, restoration, and canonical legitimacy, through which Bulgaria's alignment with Rome is presented as an act comparable to deditio – a public and voluntary act of legal and institutional binding of the ruler and his territory to the Apostolic See, resulting in the restoration of diocesan rights and ecclesiastical order. The analysis is based on a close translation that takes into account the author’s self-positioning as a witness and participant, as well as the specific terminology of Latin canon law and papal institutional discourse. In conclusion, the study proposes a cautious reassessment of the Latin model of Bulgaria’s ecclesiastical alignment with Rome as an autonomous conceptual framework. While not intended to replace established historiographical interpretations, this perspective contributes to a more nuanced understanding of the political, canonical, and legal dimensions of the process and highlights the importance of integrating Latin sources into the broader discussion of the Cyrillo-Methodian era.</jats:p>