The terms "Cyrillo-Methodian mission" and "Cyrillo-Methodian traditions usually refer, in narrow sense, to the ninth-century activities of the brothers Cyril and Methodius among the Slavs, that is, the creation of a new Slavic alphabet and the translation of the main liturgical books and their transmission first to Great Moravia and, after the death of the two apostles and the collapse of their mission there in 886, to the medieval Bulgarian empire by their disciples.