From BiblePortal Wikipedia

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [1]

Pope (708-715), a native of Syria, succeeded Sisinnius in 708. He visited Constantinople and Nicomedia, where he was received with great honor by the emperor Justinian the younger. After his return to Rome he defended the worship of images against John, patriarch of Constantinople, and against Philippicus, who had usurped the empire. Felix, archbishop of Ravenna, who had at first refused to acknowledge Constantine, and had been exiled in consequence, made his submission to him, and was reinstated in his see. Constantine died April 8, 715, and was succeeded by Gregory II. Wetzer und Welte, Kirch.-Lex. 2:833.

The Nuttall Encyclopedia [2]

The name of 13 emperors who reigned at Rome or Byzantium between 306 and 1453.