Slavorum Apostoli §23

²³ The apostolic and missionary activity of Saints Cyril and Methodius, which belongs to the second half of the ninth century, can be considered the first effective evangelization of the Slavs. This activity involved the individual territories in varying degrees, and was mainly concentrated in the territories of the then existing State of Greater Moravia. It principally included the regions belonging to the metropolis of which Methodius was pastor, namely Moravia, Slovakia and Pannonia, the last being a part of modern Hungary. Included in the sphere of the wider influence exercised by this apostolic activity, especially that of the missionaries trained by Methodius, were the other groups of Western Slavs, particularly those of Bohemia. The first historical Prince of Bohemia of the dynasty of the Premyslids, Bozyvoj (Borivoj), was probably baptized according to the Slavonic Rite. Later this influence reached the Sorbo-Lusatian tribes, and the territories of southern Poland. However, from the time of the fall of Greater Moravia in about 905- 906 the Latin Rite took the place of the Slav Rite and Bohemia was assigned ecclesiastically to the Bishop of Regensburg and the metropolis of Salzburg. However, it is worthy of note that about the middle of the tenth century, at the time of Saint Wenceslaus, there was still a strong intermingling of the elements of both rites, and an advanced coexistence of both languages in the liturgy: Slavonic and Latin. Moreover, the Christianization of the people was not possible without using the native language. And only upon such a foundation could the development of the Christian terminology in Bohemia take place, and from here, subsequently, the development and consolidation of ecclesiastical terminology in Poland. Information about the Prince of the Vislits in the Lite of Methodius is the most ancient historical reference to one of the Polish tribes. Insufficient data exist for it to be possible to link this item of information with the institution in the Polish territories of a Slav Rite ecclesiastical organization.