Boris I, also known as Boris I of Bulgaria, was the ruler of the First Bulgarian Empire from 852 to 889. He is best known for converting the Bulgarian people to Christianity, which helped to unify the nation and strengthen its ties with the Byzantine Empire. His reign marked a significant cultural and religious transformation in Bulgaria. After his conversion, Boris I established the Bulgarian Orthodox Church and promoted the use of the Cyrillic alphabet, which facilitated literacy and education. He is often credited with laying the foundations for the development of Bulgarian culture and identity, making him a pivotal figure in the history of Bulgaria.