EN
The paper is concerned with the contribution of the mission of the Thessalonian brothers Constantine (Cyril) and Methodius for the Slavonic world in terms of three important points: 1) Brothers Cyril and Methodius worked in the Slavonic world as mediators of the cultural values of the Byzantine Empire. 2) They created not only a means of expression in the form of writing, but also a literary language that had not existed before. 3) They created all the conditions necessary for the free development of national Slavonic cultural life and for the formation of the self-consciousness necessary for its continuation. These three points express not only the contribution of Cyril and Methodius to the development of the culture and national consciousness of the Slavs, but also the cultural message of Byzantium to the Slavs.