Photius I (820-893), Patriarch of Constantinople, a man of immense learning and a skilled politician, was one of the most imposing figures in the history of Byzantium. He received a superb education and devoted himself to the study of Classical Greek and ecclesiastical literature. One of the few known details of his background is that his father, Sergius, was banished for idolatry and died in exile. A powerful scholar, many of his works are still of exceptional importance today, among them the Lexicon and the Bibliotheca or Myriobiblos (‘Ten Thousand Books’). The latter is of additional value in that it preserves many excerpts from classical literature that Photius read and commented on, which would otherwise have been lost. He also wrote works of theology and letters.