The present paper aims to shed light on still underexplored aspects of Medieval Bulgaria’s contribution to the transmission of European culture. Emphasis is placed upon the need to position Old Church Slavonic translations within the general framework of the 9th-century Byzantine cultural revival. During this period, Byzantine theologians and humanists were engaged in collecting books, interpreting the Bible, studying Classical and Early Christian authors, and copying, reviewing, and preserving texts to ensure the intellectual and philosophical heritage was in harmony with Christian teachings. Constantinople, with its diverse cultural environment – a vibrant fusion of Greco-Roman traditions, Eastern influences, and Orthodox Christianity – was the place where Constantine the Philosopher was educated and where he had the opportunity to enter the circle of prominent intellectuals of the time, such as Leo the Mathematician and Patriarch Photius. In the decades immediately following, the Byzantine capital must have also exerted a decisive influence on the theological and literary education of high-ranking members of the Bulgarian aristocracy and clergy. The early history of Old Bulgarian translated literature can be deemed to have its roots in the refined intellectual milieu of the First Byzantine Humanism. This connection is not immediately apparent but emerges when investigating Old Church Slavonic translations from an interdisciplinary standpoint, placing them within the broader context of the dynamics of text conservation and loss from Late Antiquity to the Early Middle Ages. The new perspective presented here is based on establishing the philological contribution of Old Bulgarian translations to the reconstruction of Biblical, Early Christian, and Medieval texts. Such an approach shows that Old Bulgarian literature should be seen not merely as a functional, intermediary tradition for the transplantation of Byzantine culture to the Slavs, but more broadly as an integral part of the complex process of transmission and dissemination of European culture from Late Antiquity up to the Early Middle Ages.