Boris I

Boris I (died 907), khan of Bulgaria (852-889). During his reign Boris conducted unsuccessful campaigns against Serbia and Croatia. Under pressure from Byzantine Emperor Michael III, Boris embraced Christianity in 865 and made it the official religion. In 870, after wavering between adherence to the Western and Eastern Churches, Boris decided on the latter when the pope failed to meet his demand for the appointment of an archbishop for Bulgaria. In 889 Boris voluntarily relinquished the throne in favour of his son Vladimir, and retired to a monastery. Vladimir, however, proved to be an incompetent and vicious monarch, and the nobility revolted against him in 893. Emerging from retirement, Boris deposed and blinded Vladimir and replaced him with Simeon, Boris's younger son. Boris then re-entered the monastery. He is venerated as a saint by the Eastern Church.