It was the providence of God that the chalif himself never allowed the sworn protector of the Church who sat on the eastern throne to execute this threat. Rather he was all through this century in dread lest the Mohammedan, having fixed his throne at Damascus, should advance it to Constantinople. It was again the providence of God that Constantinople itself should not fall during this time of its utmost weakness, and so open the whole of northern Europe to Mohammedan domination. The city of Constantine was then the material rampart which stopped the impetuous current of Saracen invasion to the north. The chalif Muawiah, who reigned over the immense Saracen empire from 661 to 680, was strong enough continually to beat the Emperor, to ravage his Asiatic territory, to advance towards his capital, but he was never able to take it. The advance of the seat of the Saracenic empire from the remote Medina to the near and beautiful Damascus, the paradise of eastern cities, dwelling in its perpetual garden among ever-flowing waters of Abana and Pharpar, was itself a sign how the empire had fallen. A religion founded on the denial of the Christian faith, of which it was, moreover, the special rival, had full possession of the once Roman and Christian East. Muawiah became chalif on the death of Ali in 661. He had conducted the civil war against Ali, which distracted for five years the Saracen power, with the forces of Syria, as its governor; and when he became supreme made it the capital of his empire. Constans II., having crowned with martyrdom the greatest confessor of the West, Pope Martin, and the greatest confessor of the East, St. Maximus, resolved in the year 662, to visit the West. The tyranny of Constans in regard to the Pope was not completed even by his treatment of St Martin. When he had condemned this Pope, but before he had caused his death he is supposed to have compelled the Roman clergy to elect another Pope. This was Eugenius, who was recognised in the year 654 for Pope, while St. Martin was yet alive.(113) Whether the urgency and threats of the imperial ministers overcame at length the constancy of the clergy, or whether, as is more probable, they feared to see some heretic sent by the emperor to occupy the throne of St. Peter, they elected Eugenius, by birth a Roman, a person of great goodness and holy life, who held the See two years and eight months. The synodical letter of Peter, the fourth Monothelite patriarch of Constantinople in succession was sent to him, but being obscure in its expressions about our Lord, was sent back with indignity.(114) It would seem that the exceeding danger of the time caused the election and consecration of Pope Eugenius in the lifetime of St. Martin, to pass for legitimate. Eugenius died in 657, and was succeeded by Pope Vitalian, after a vacancy of a month and 29 days.