Deacon Marinus (later Pope Marinus I), after which Bulgaria began to shift towards Constantinople once again. At the Fourth Council of Constantinople in 870 the position of the Bulgarian church was reopened by Bulgarian envoys, and the eastern patriarchs adjudicated in favor of Constantinople. This determined the future of the Bulgarian Orthodox Church, which was granted the status of an autocephalous archbishopric by the Patriarchate of Constantinople and an archbishop of its own. Later in the 870s, the Patriarch of Constantinople surrendered Bulgaria to the Papacy, but this concession was purely nominal, as it did not affect the actual position of Bulgaria's autocephalous church. The Christianization of the Bulgarians as a result of Boris’ actions had profound effects not only on the religious belief system of the Bulgarians but also the structure of the Bulgarian government. Upon embracing Christianity, Boris took on the title of Tsar and joined the community of nations that embraced Christ, to the great delight of the Eastern Roman Empire, which was later given the name Byzantium by historians. Toward the end of his reign, Boris began to increase the number of native Bulgarian clergy. Consequently, Boris began to send Bulgarians to Constantinople to obtain a monastic education and some of these Bulgarians returned to their homeland to serve as clergymen. In 885, Boris was presented with a new opportunity to establish a native clergy when Slavic-speaking disciples of St. Cyril and St. Methodius were forced to flee from Moravia after a German-inspired reaction to the death of the apostle. Changes to Bulgarian culture brought on by Clement and Naum In 886 Boris' governor of Belgrade welcomed the disciples of Saint Cyril and Saint Methodius, who were exiled from Great Moravia into Bulgaria and sent them on to Boris in Pliska. Boris happily greeted two of these disciples, Clement of Ohrid and Naum of Preslav, who were of noble Bulgarian Slavic origin. To utilize the disciple's talents, Boris commissioned Clement to be a “teacher” in the province of Kutmichevitsa. Both Clement and Naum were instrumental in furthering the cultural, linguistic and spiritual works of Cyril and Methodius. They set up educational centers in Pliska and in Ohrid to further the development of Slavonic letters and liturgy. Clement later trained thousands of Slavonic-speaking priests who replaced the Greek-speaking clergy from Constantinople still present in Bulgaria. The script that was originally developed by Cyril and Methodius is known