[14] The mission of Clement was the crucial factor which transformed the Slavs in then Kutmichevitsa (present-day Macedonia)[c] into Bulgarians.

[15] Clement is also the patron saint of North Macedonia, the city of Ohrid[5] and the Macedonian Orthodox Church.

That is why most scholars think he was born in the Byzantine Empire in the territory where Methodius served during his political career, i.e. that he was a Slav from Southern Macedonia.

According to others, the area of Southern Macedonia, including the northern approach to Thessaloniki, where he may have been born, was then part of the First Bulgarian Empire.

In 867 or 868 he became a priest in Rome, ordained along with two other disciples of Cyril and Methodius, Gorazd and Naum, by bishops Formosus and Gauderic.

Angelarius soon died after an arrival, but Clement and Naum were afterwards sent to the Bulgarian capital of Pliska, where they were commissioned by Boris I to instruct the future clergy of the state in the Slavonic language.

Fearing growing Byzantine influence and weakening of the state, Boris viewed the adoption of the Old Slavonic language as a way to preserve the political independence and stability of Bulgaria.

[29] The development of Old Church Slavonic literacy had the effect of preventing the assimilation of the South Slavs into neighbouring Byzantine culture, which promoted the formation of a distinct Bulgarian identity in the Empire.

[30] During the first quarter of the 10th century, the ethnonym “Bulgarians” was adopted by the Slavic tribes in most of Macedonia, while their names were abandoned.

The finding gives reason to assume that the disciples of Cyril and Methodius were settled there at one stage, after being expelled from the Great Moravia and their reception in Bulgaria.