John the Exarch was a prominent scholar, translator, and writer active in the First Bulgarian Empire during the late 9th and early 10th centuries. Working at the Preslav Literary School during the reigns of Boris I and Simeon I, he was a key figure in medieval Bulgarian letters. His extensive literary output, which combined original compositions with translations of Byzantine texts, demonstrates a profound mastery of the Greek language. While his exact biographical details remain uncertain, he is remembered as a significant intellectual of his era.