John of Ephesus (ĕfˈəsəs) [key], c.505–c.585, Syrian Monophysite historian, bishop of Ephesus. He became a leader of the Monophysites (see Monophysitism), and Byzantine Emperor Justinian, whose favor he enjoyed, set him over the Monophysite community in Constantinople. John suffered greatly in the persecution of his sect after 571. His Ecclesiastical History makes an unusual effort to avoid prejudice. It is especially valuable for the events of the 6th cent. He is also called John of Asia.