[Roman Martyrology. S. Cyril by the Greeks on Feb. 14th, and S. Methodius on May 11th. Authorities:--The Life of S. Clement, a pupil of Methodius, pub. by Pampereus, Vienna, 1802; the Pannonian Life of Methodius; notices in the Life of S. Ludmilla; the Chronicle of Nestor; Cosmas of Prague, &c. The chronology in this article is from the treatise on Cyril and Methodius by Philaret, B. of Rigá, Milan, 1847.] Cyril and Methodius, the apostles of the Sclaves, were brothers, the sons of a man of rank in Thessalonica. Constantine, who afterwards in religion assumed the name of Cyril, the younger, was educated at the court of Constantinople, along with the youthful emperor Michael, from the year 842, by the illustrious Photius, who instructed him in logic, philosophy, mathematics, and languages. His talents and accomplishments afforded him every prospect of a brilliant career in the world, but he chose to lay them at the foot of the cross, and, receiving sacred orders, was appointed librarian to the palace. Soon after, he retired to a little monastery, but was drawn from it again to give lectures on philosophy. Methodius, his elder brother, as soon as his education was accomplished, entered the army, and was appointed to the government of the Græco-Sclavonic province, which, according to the Pannonian legend, he held for ten years. In the year 851, Cyril retired to Mount Olympus, along with his brother, who had also resolved to desert the world, and lived in seclusion and the practice of self-discipline. In 858, some dignitaries of the Chazars, a Hunnish race, besought the emperor to send them a learned man to instruct them in the true faith, and Cyril and Methodius were chosen for this purpose. How long they spent on this mission is not known exactly. They tarried till they could organise the church among the Chazars, and then retired to the Crimea where they worked together at making a Sclavonic translation of the Holy Gospels. It was whilst there that they discovered what they believed to be the relics of S. Clement of Rome, lying together with the anchor, which had been attached to his neck, where the faithful had reverently laid him. They raised the holy remains, and translated them to Constantinople. In 862, the Sclavonic princes of Pannonia, Rostislaw, Swaetopolk, and Kotel requested the emperor Michael and the patriarch Photius, to send them teachers, "because they were without true instructors for the people," and they desired to have instruction and divine worship in their own language. It appears that missionaries of the Latin Church had already penetrated amongst them, but probably had been unable to master the Sclavonic tongue; at any rate, the Pannonians refused to accept them, and turned instead to the East.