Research carried out by Romanian and foreign experts at Mount Athos deals with almost 600 years of Romanian-Athonite relations. The oldest monastic patronage was undoubtedly that of the Georgians, who arrived in quite a large number in the holy peninsula since 972. The fall of Byzantium, in 1453, ceased the aids of the Byzantine emperors, which continued by Romanian rulers, such as Stephen the Great, Neagoe Basarab, or Michael the Brave. These gifts, made by the Romanian princes to support monasticism in the holy Greek peninsula, played nonetheless an important political role. The contribution of the “Romanian Byzantium” – as it was called by Nicolae Iorga – was not only of a donor, but also of a preserver of the Athonite cultural values. Following the journeys to Mount Athos of the Romanian scholars Teodor T. Burada, in 1882, Marcu Beza, in 1933, and of the Byzantinologist Gabriel Millet, in 1915, a remarkable Romanian cultural and spiritual treasure was brought to light, being preserved over the centuries. Precious manuscripts, from liturgical to science books, including an impressive collection of incunabula and ecclesiastical objects of great value, provide evidence of the Romanian-Athonite secular relations. Our present research explores an important collection of manuscripts (most of which are music manuscripts), held at the Holy Monastery of Agiou Pavlou (Athos). The rich repertoire of songs written by great Byzantine and post-Byzantine composers is spread through more than 75 such manuscripts, among which Doxastaria, Anthologia, Irmologia and Sticheraria.