Boris I of Bulgaria, also known as Boris I Mihail, was the ruler of the First Bulgarian Empire from 852 to 889. He is best known for his efforts to convert the Bulgarian people to Christianity, which helped to unify the nation and strengthen its cultural identity. His reign marked a significant transition from paganism to Christianity, aligning Bulgaria more closely with the Byzantine Empire. Boris I established the Bulgarian Orthodox Church and sought to create a written language for the Slavic people, which led to the development of the Cyrillic alphabet. His reign laid the foundation for the future growth of Bulgaria as a powerful state in Eastern Europe.