Origins and Education
The brothers were born in Thessalonica in the early 9th century to a senatorial family. Their father, Leo, held the office of droungarios in the Byzantine theme of Thessalonica, and their mother was named Maria. Sources note that they were raised in a bilingual environment where both Greek and Slavic were spoken. The brothers lost their father while Constantine (the future Cyril) was still young, after which the powerful minister Theoktistos became their protector.
Theoktistos, together with the regent Bardas, advanced a far-reaching educational program within the Empire that culminated in the establishment of the University of Magnaura, where Constantine taught philosophy. Constantine was learned in theology and acquired proficiency in additional languages, and was ordained; according to sources he became a priest, while his elder brother Michael served first in the Slavic administration before entering monastic life on Mount Olympus, taking the name Methodius.
Missionary Work and the Slavonic Mission
Around 860, Emperor Michael III and Patriarch Photius of Constantinople sent the brothers on a missionary expedition to the Khazars. Accounts relate that Constantine learned the Khazar language, and the mission resulted in many conversions to Christianity.
In 862, Prince Rastislav of Great Moravia requested missionaries who could teach his people and conduct divine services in the Slavonic tongue. The brothers answered the call and, beginning in 863, translated the Gospels and essential liturgical books into Old Church Slavonic. To render the language in writing they created the Glagolitic script, the first alphabet used for Slavonic manuscripts, which later developed into the Cyrillic alphabet used across the Slavic nations. Methodius is recorded as later completing the translation of the Holy Scriptures, with the exception of the Books of Maccabees, and as translating ecclesiastical and civil law.
Journey to Rome and Later Career
The brothers traveled to Rome around 867–868, bringing with them the relics of Pope Saint Clement I and a number of disciples. Pope Adrian II formally authorized the use of the new Slavic liturgy and consecrated Methodius as bishop, appointing him archbishop of the newly formed Archdiocese of Moravia and Pannonia, independent of the German Church. Five Slavic disciples were ordained at Rome: Saint Gorazd, Saint Clement of Ohrid, and Saint Naum as priests, and Saint Angelar and Saint Sava as deacons.
Constantine became a monk in Rome, taking the name Cyril, and died there on 14 February 869. Methodius returned to his mission but faced sustained opposition from German clergy, who at one point deposed and imprisoned him; Pope John VIII secured his release some years later. Methodius died on 6 April 885, recommending his disciple Gorazd as his successor, and was buried in the principal cathedral church of Great Moravia.
Legacy
Cyril and Methodius are venerated in the Eastern Orthodox Church as saints bearing the title Equal-to-the-Apostles. Their joint commemoration is kept on May 11, with Cyril remembered on February 14 and Methodius on April 6. The Glagolitic script they devised and the Old Church Slavonic literary tradition they founded became the foundation of Slavic Christian literacy.
Their veneration also extends to the Western Church: in 1880 Pope Leo XIII introduced their feast in the Latin Church, and in 1980 Pope John Paul II declared them co-patron saints of Europe.
