As eighteen years of continual defeat by the Persians, from 604 to 622, had reduced the Eastern empire to a state of demoralised weakness, so the seven succeeding years, from 622 to 629, in which Heraclius wrought a full revenge on the Persian king, inflicted no passing collapse upon the empire resuscitated by the Sassanides in the third century. King Siroes did not long enjoy the fruit of his parricide. He reigned six months and then he died—some say of the plague, some of remorse. After his death the throne of Persia seemed to become a seat of murder. His young son, Ardeschir, or Artaxerxes, was killed after reigning seven months by his uncle, the general Sarbar. Sarbar kept the throne two months and was killed. Devanschir took his place. He was followed by Borane, a daughter of Chosroes. She was replaced by a certain Tschaschindeh, who was followed by Borane’s sister, Azermidokt. A certain Kesra, or Chosroes, succeeded, and he gave way to a Ferokzad. Finally, Jezdedjerd, a grandson of the last Chosroes, was crowned in the year 632. Thus in the short space of four years about nine persons succeeded to the throne by murder. Jezdedjerd III. began his reign in the year Mohammed died. He is called by Theophanes, Hormisdas. He had the honour to be the last king of Persia and to end his days by the sword of the Arab in 651. His son, Peroxes, became a captain in the life-guards of the emperor of China at Singapore, and left no posterity. After this glimpse at the action of the Byzantine and Persian empires on each other during the thirty years which follow immediately on the death of St. Gregory, we turn to consider the conduct of the temporal liege-lord of the Pope towards him whom he recognised as successor of St. Peter. The emperor Phocas, following in this his predecessor Justinian, had expressly enjoined on the patriarch of Constantinople to recognise the Primacy of Rome.(6) What the chroniclers remark is important, that Boniface III., the next to succeed St. Gregory, received a decree from Phocas, in which he solemnly declared that the See of the Roman Church was to be considered the head of Christendom. It may be remarked here that Phocas did not say a word more than his predecessor, Marcian, said to St. Leo a hundred and fifty years before. Phocas may be named a tyrant, but Marcian has left an unspotted reputation as a Christian king and Roman prince, who received the empire with the hand of Pulcheria, heiress of the great Theodosius, and the only descendant worthy of his greatness, whose name stands also on the diptychs of the Catholic Church as a virgin saint.(7) Upon the history of the City of Rome during the first half of the seventh century the greatest obscurity rests.(8) It was indeed the most frightful and destructive century for the former queen-city of the world. The Book of the Popes by Anastasius(9) trickles in a slender thread amid war, famine, and pestilence, and inundations of the Tiber; but it is all we have to look at.