ENIn the 16-th century the monastery of Suprasi was the second monastic center of the Orthodox Church in the Great Duchy of Lithuania after the Kiev-Caves Monastery. This monastery was founded in 1498 by the Novogrod Voivod and Marshall of the Great Duchy of Lithuania - Alexander Khadkevich together with Smolensk archbishop - Joseph Soltan. In the history of the Byelorussian culture the monastery in Suprasi occupies unique place. The best achievements of many branches of culture have been concentrated in it. They mirror close contacts with the religious and cultural heritage of other Slavonic nations. The monastery became a place of the reciprocal permeating of various religious trends. Also here, many national cultures influenced each other. An example of this reciprocal permeating of cultures was the architecture and interior decorations of the Annunciation of the Mother of God church. The uniqueness of the architecture of this building consists in the mixing of the Gothic and Byzantine styles. The direct connections of Suprasi with Byzantine and Serbian culture may be proved by the monumental frescos in the Annunciation Church. They were painted by a group of painters under the supervision of Nektorius the Serb (Serb Nekhtariosh). These frescos were a testimony to dogmatic Orthodoxy. The monastery of Suprasi, in the Grand Duchy of Lithuania, had a similar character. In the second half of the sixteenth century, it was dominated by anti-Latin, antiunion, and anti-reforming tendencies. These views were expressed in the paintings, polemical literature, and activity of the monks. The iconographic symbolism of the church of the annunciation further served this common purpose. The interior of the cathedral shows a direct connection with the Ruthenian and Serbian cultures. Its architecture is similar to the fortified churches of St. Sophia in in Polotsk, Synkovitche and Malomozheykov.The monastery in Suprasi was one of the largest Orthodox monastic centre in the Grand Duchy of Lithuania in the 16t h century and had close ties to similar institutions in Poland and abroad. [...] The influence of eastern-Slavic and Balkan cultures is visible in the monastery's architecture and iconography, the interior design and furnishings of its church and in the collection of the monastery library. The collection became the subject of many research works. The library itself had been described numerous times. The oldest inventory, which became the basis for the creation of this catalogue, dates to 1557. Its original version, kept in the Suprasi monastery until 1877, has been removed to Vilnius. Its current whereabouts are unknown. The full list o f the monastery's books, as of 1557, created by archimandrite Sergiusz Kimbar, was published twice - in 1867 and 1870. Later inventories were put together in 1645,1668,1674,1819 (partial), 1829,1830 and 1836. The library collection was also catalogued by Ignacy N. Danilowicz in 1824 and Michał Bobrowski in 1836 [...].The traditional opinion about the origin of one of the most important Old Bulgarian manuscripts - the Codex Suprasliensis - sets it in the 11-th century. The manuscript developed in North-Eastern Bulgaria is written in large and clear ustav on vellum by a single scribe, containing the Menology for March (including hagiology and homilies of various origins). Its modern backgrounds have been studied in general, beginning with 1823 when the manuscript was discovered by M. K. Bobrovsky in the library of Suprasi and later partitioned, the parts now located in the three collections of worldwide renown: National Library of Poland (Biblioteka Narodowa) in Warsaw, National and University Library in Ljubljana, and the National Library of Russia in Sankt-Petersburg. In the monastery's library, there was a copy of The Chronicle of Kiev and Novogrod. The Suprasi version of the Belarusian-Lithuanian 1519 Chronicle invokes the Old Ruthenian tradition. The church library had also other Ruthenian annals: Tsarstvennik s letopistsem and Vremennik s letopistsem. The awareness of common historical and cultural heritage with other East-Slavic nations and religious unity added to the popularity of the biographies of Ruthenian, Bulgarian, Serbian and Greek saints. The openness of the Suprasi clergy for new religious and cultural trends is testified to by voluminous positions in the monastery library which possessed 587 volumes in 1645. Developing a catalogue of Supraslan manuscripts in Polish and foreign collections, is an attempt to present the richness and uniqueness of this library, which was so important in learning the history, literature, culture and religious writings of many nations. "Manuscripts from Suprasi in Polish and Foreign Collections" make use of the findings of earlier researchers completed and verified by the authors of this catalogue.