Knyaz Boris I (also Bogoris), venerated as Saint Tsar Boris I (Mihail) the Baptizer ( ; died 2 May 907), was the ruler of the First Bulgarian Empire in 852–889. At the time of his baptism in 864, Boris was named Michael after his godfather, Emperor Michael III. The historian Steven Runciman called him one of the greatest persons in history. Despite a number of military setbacks, the reign of Boris I was marked with significant events that shaped Bulgarian and European history. With the Christianization of Bulgaria in 864 paganism (i.e. Tengrism) was abolished. A skillful diplomat, Boris I successfully exploited the conflict between the Patriarchate of Constantinople and the Papacy to secure an autocephalous Bulgarian Church, thus dealing with the nobility's concerns about Byzantine interference in Bulgaria's internal affairs. When in 885 the disciples of Saints Cyril and Methodius were banished from Great Moravia, Boris I gave them refuge and provided assistance which saved the Glagolithic and later promoted the development of the Cyrillic script in Preslav and the Slavic literature. After he abdicated in 889, his eldest son and successor tried to restore the old pagan religion but was deposed by Boris I. During the Council of Preslav which followed that event, the Byzantine clergy was replaced with Bulgarians, and the Greek language was replaced with what is now known as Old Church Slavonic. He is regarded as a saint in the Orthodox Church, as the Prince and baptizer of Bulgaria, and as Equal-to-the-Apostles, with his feast day observed on May 2 and in Synaxis of all venerable and holy Fathers of Bulgaria (movable holiday on the 2nd Sunday of Pentecost). Name and titles The most common theory is that the name Boris is of Bulgar origin. After his official act of conversion to Christianity, Boris adopted the Christian name Michael. He is sometimes called Boris-Michael in historical research. The only direct evidence of Boris's title are his seals and the inscription found near the town of Ballsh, modern Albania, and at Varna. There he is called by the Byzantine title "Archon of Bulgaria", which is usually translated as "ruler", and in the 10-11th centuries also as "Knyaz" (Кнѧзъ, Bulg.). In the Bulgarian sources from that period, Boris I is called "Knyaz" or "Tsar" ("Царь", Bulg.), and during the Second Bulgarian Empire, "Tsar". In modern historiography Boris is called by different titles. Most historians accept that he