5. A pretender to the purple in the time of the emperor Leo III., the Isaurian. Intelligence of the siege of Constantinople by the Saracens, soon after Leo's accession, having reached Sicily, Sergius, general of the Byzantine forces in that island, revolted, and appointed Gregory, who had been one either of his servants or his soldiers, emperor, changing his name to Tiberius (A. D. 718). Theophanes and Cedrenus call this puppet emperor not Gregory, but Basil the son of Gregory Onomagulus, and state that he was a native of Constantinople; but Zonaras calls him Gregory, though he agrees with the other historians as to his taking the name of Tiberius. When the intelligence of these transactions reached Constantinople, Leo, who was already relieved from the pressure of the Saracens, sent one of his officers, Paul, who had held the office of "Chartularius," to put down the revolt. Paul landed at Syracuse with the intelligence of the deliverance of Constantinople, and with letters to the troops, who immediately returned to their allegiance, and seizing Gregory and those whom under Sergius's direction he had appointed to office, delivered them up in bonds to Paulus. Sergius himself fled to the Lombards on the borders of Calabria. Paul put Gregory to death, and sent his head to the emperor, and punished his supporters in various ways. (Theophanes, Chronog.
vol. i. p. 611-613, ed. Bonn; Cedren. vol. i. p. 790, &c., ed. Bonn; Zonar. 15.2