Cyril and Methodius - The Apostles of the Slavs

Saint Constantine (Cyril) and Methodius were two Byzantine brothers born in the 9th century who became prominent Christian missionaries. Their mission influenced the cultural development of all Slavic nations, for which they are called the apostles of the Slavs. They stood at the birth of the Glagolitic script, the first Slavic alphabet used for the translation of the Old Testament, and in the Orthodox Church they are venerated as saints and were given the title "Equal-to-the saints". The Pope Leo XIII included their feast day into the Roman-Catholic calendar and Pope John Paul II proclaimed them the Saint Co-Patrons of Europe. (official distributor synopsis)