Cyril (born Constantine, 826–869) and Methodius (815–885) were two brothers and Byzantine Christian theologians and missionaries. For their work evangelizing the Slavs, they are known as the "Apostles to the Slavs". They are credited with devising the Glagolitic alphabet, the first alphabet used to transcribe Old Church Slavonic. After their deaths, their pupils continued their missionary work among other Slavs. Both brothers are venerated in the Eastern Orthodox Church as saints with the title of "equal-to-apostles". In 1880, Pope Leo XIII introduced their feast into the calendar of the Roman Catholic Church. In 1980, the first Slav pope, Pope John Paul II declared them co-patron saints of Europe, together with Benedict of Nursia. Early career Early life The two brothers were born in Thessalonica, then located in the Byzantine province of the same name (today in Greece) – Cyril in about 827–828 and Methodius in about 815–820. According to the Vita Cyrilli ("The Life of Cyril"), Cyril was reputedly the youngest of seven brothers; he was born Constantine, but was given the name Cyril upon becoming a monk in Rome shortly before his death. Methodius was born Michael and was given the name Methodius upon becoming a monk in Polychron Monastery at Mysian Olympus (present-day Uludağ in northwest Turkey). Their father was Leo, a droungarios of the Byzantine theme of Thessalonica, and their mother's name was Maria. The exact ethnic origins of the brothers are unknown, there is controversy as to whether Cyril and Methodius were of Slavic<ref> 1. Mortimer Chambers, Barbara Hanawalt, Theodore Rabb, Isser Woloch, Raymond Grew. The Western Experience with Powerweb. Eighth Edition. McGraw-Hill Higher Education 2002. University of Michigan. p. 214. ...Two Christian brothers of Slavic descent, Cyril and Methodius, set out in about 862 as missionaries from the Byzantine... 2. Balkan Studies, Volume 22. Hidryma Meletōn Chersonēsou tou Haimou (Thessalonikē, Greece). The Institute, 1981. Original from the University of Michigan. p. 381 ...Being of Slavic descent, both of them spoke the old Slavic language fluently... 3. Loring M. Danforth. The Macedonian Conflict: Ethnic Nationalism in a Transnational World. Princeton University Press, 1995. p. 49 . ...In the ninth century two brothers Cyril and Methodius, Macedonian educators of Slavic origin from Solun, brought literacy and Christianity to the Slavs... 4. Ihor Ševčenko. Byzantium and the Slavs: In Letters and Culture'''. Harvard Ukrainian Research Institute, 1991. p. 481. ...63-68 (Cyril and Methodius were Slavs)...There remains that argument