These two brothers, Constantine and Michael, were from a wealthy and powerful family in Salonika, now Thessalonica and were born in the early 9th century. They were well educated in Greek and the Slavic tongue of Macedonia. Constantine (later St. Cyril) became fluent also in Arabic and Hebrew. St. Cyril was sent by the Byzantine Emperor Michael II to Baghdad to talk with Arab theologians about the Holy Trinity, and also to the Khazars to try to stop Judaism from becoming the state religion.
St. Methodius (Michael) became a monk on Mount Athos. In a.d. 862 the Emperor and St. Photius the Great sent him with St. Cyril to Moravia at the bidding of Prince Radislav, who was a Sla-vic speaker attempting to change the Western German missionaries who were trying to teach them about Christianity. The brothers succeeded to bring many to the Faith and gave the first Glagolithic Slavonic alphabet, then translated the Scriptures and services from Greek into Slavonic. They went to Rome, where they were blessed to use this Slavonic language in church services. St. Cyril died in Rome in a.d. 869 and St. Methodius died in Moravia in a.d. 885.