Cyrilus and Methodius

Cyril (827-869) and Methodius (c. 826-884), brothers, born in Thessalonika -Macedonia, known as the "apostles of the Slavs".

Both were outstanding scholars, theologians, and linguists. In 860, Cyril (originally named Constantine), who had gone on a mission to the Arabs and been professor of philosophy at the patriarchal school in Constantinople, worked with Methodius, the abbot of a Greek monastery, for the conversion of the Khazars northeast of the Black Sea. In 862, when Prince Rostislav of Great Moravia asked Constantinople for missionaries, the emperor Michael III and the patriarch Photius named Cyril and Methodius. In 863, they started their work among the Slavs, using Slavonic in the liturgy. They translated the Holy Scriptures into the language later known as Old Church Slavonic (or Old Bulgarian) and invented a Slavic alphabet based on Greek characters that in its final Cyrillic form is still in use as the alphabet for modern Russian and a number of other Slavic languages.

The posthumous influence of Cyril and Methodius reached distant Kiev in Russia and left traces among the Slavs of Croatia, Bohemia, and Poland. Their feast day in the Orthodox church is May 11.