In 616 it was taken by Chosroes, king of Persia; and in 6 4 o by the Arabians, under `Amr, after a siege that lasted fourteen months, during which Heraclius, the emperor of Constantinople, did not send a single ship to its assistance.
At the end of Heraclius' reign he obtained through his mother's influence the title of Augustus (638), and after his father's death was proclaimed joint emperor with his half-brother Constantine III.
After a severe struggle the Persians were defeated by the emperor Heraclius, who entered Jerusalem in triumph in 62 9 bringing with him the holy cross, which had been carried off by Chosroes.
The author designates the story of the later empire at Constantinople (after Heraclius) as " a uniform tale of weakness and misery," a judgment which is entirely false; and in accordance with this doctrine, he makes the empire, which is his proper subject, merely a string for connecting great movements which affected it, such as the Saracen conquests, the Crusades, the Mongol invasions, the Turkish conquests.
He compressed into a single chapter the domestic history and policy of the emperors from the son of Heraclius to Isaac Angelus; and did no justice to the remarkable ability and the indefatigable industry shown in the service of the state by most of the sovereigns from Leo III.