Byzantine emperor from 886; known also as “the Wise” and “the Philosopher.” Eldest son of Basil I, he was educated under Photius,* became co-emperor in 870, and after ascending the throne renounced his former teacher to gain support with intransigents in the church. Facing threats from Arabs and Bulgarians, he staved them off with diplomacy rather than a military campaign. He reformed the state’s legal and administrative functions, and in 888 completed the Basilica, a corpus of Roman law still valid in the empire, by enlarging the number of Greek books from forty to sixty. Leo married four times to secure an heir and was severely censured by churchmen for this action, although his son was legitimatized in time to inherit the throne. Leo constructed a church and a monastery in Constantinople to honor the biblical person Lazarus. His writings included laws and decrees regarding secular and religious affairs; a treatise on military strategy that incorporated much of Aelian’s text on military affairs and urged feigned retreats without apology; homilies; religious verse; orations; secular poetry; and a funeral oration on his father’s accomplishments.