Boris of Bulgaria played Rome against Constantinople to win his own church
In August 866 a Bulgarian embassy arrived in Rome carrying a long list of questions from its ruler, Boris I, for Pope Nicholas I. They went home with 106 detailed answers on faith, law, politics and customs. Boris had already been baptised by Byzantine clergy, and he was shopping for a better deal.
His conversion had been forced by circumstance. Boris, who ruled the First Bulgarian Empire from 852, had been courting an alliance with the Frankish king Louis the German, who promised missionaries from the Roman church. Late in 863, during a famine, the Byzantine emperor Michael III attacked. Caught off guard, Boris made peace by agreeing to accept Christianity in its eastern form, and early in 864 he was quietly baptised at Pliska with his family and chosen nobles, taking the name Michael after his imperial godfather.
Faith also served a domestic purpose. His realm combined a minority Bulgar military aristocracy, who worshipped the sky god Tangra, with a Slavic majority holding their own beliefs. A shared religion promised unity. Legends offer other motives, such as a sister converted in Constantinople or an icon of the Last Judgement that frightened him, but historians tend to see a calculated political choice.
What Boris wanted was a church of his own. When the Byzantine patriarch Photios gave unsatisfying answers, he turned to the Pope, exploiting the widening rift between the two centres of Christianity until he secured a self-governing Bulgarian church. In 885, when disciples of Cyril and Methodius were expelled from Great Moravia, he took them in, preserving the Glagolitic script and paving the way for Cyrillic and a Slavic literature that freed Bulgaria from depending on Greek.
Boris gave up the throne in 889 and retired, but when his eldest son tried to restore paganism he came back and deposed him. A council at Preslav then replaced Byzantine clergy with Bulgarians and made Old Church Slavonic the language of worship. He died on 2 May 907 and is venerated as a saint, remembered as the baptiser of Bulgaria.
Source: Boris I of Bulgaria
