Theodoros, Bishop of Cyzicus in the 10th century, is one of the lesser-known figures of Byzantine literature. Little is known about his life, but his correspondence with Konstantinos VII. Porphyrogennetos bears witness to the close contact between the cleric and the emperor. M. Tziatzi-Papagiannis' new critical edition of the entire correspondence not only satisfies the need to bring together previously separate collections, it also offers present-day scholars up-to-date text critical approaches.