Constantine Palæologus was the eldest surviving son of the Emperor Manuel. He could only ascend the throne by the consent of the Sultan, and when that was obtained he was crowned in Sparta, where he had ruled. On the 12th of March 1449 he entered Constantinople. The city was receiving its new lord with exultation and joy, says his friend and chronicler Phrantzes. So long as Murad still reigned they were indeed safe, but when Mohammed II. became Sultan it was clear that there would be war. Constantine turned--it was his only hope--to the West for aid. He sent an embassy to Rome begging for help, and showing willingness to renew the union of the Churches. The Pope, Nicholas V., sent back Cardinal Isidore, who had once been a Russian bishop, but, having accepted the decrees of Florence, had remained loyal to them, and was an exile from his country in consequence. He arrived at Constantinople in November 1452, bringing some money and a few troops. On December 12, 1452, the union was ratified in S. Sophia, and Cardinal Isidore said mass according to the Latin rite. From that day the people regarded the church as desecrated. In the church and monastery of the Pantokrator the monk Gennadios preached against the crime and folly of the union. Many of the great nobles cried out against it; one even declared that the Sultan would be a far better lord than the Pope. As Constantine rode through the streets daily the mob mocked and reviled him; and some cried out "rather than that we should be Latins would we be Turks." The holy sacrifice of the Body and Blood of Christ they rejected, declaring that it was polluted. Even if an angel from heaven had descended and declared that he would save the city if only the people would unite with the Roman Church the people would have refused. So the chroniclers describe the disunion within. Without, the preparations were complete. The conquerors of Constantinople had had a romantic history. A horde of barbarians, coming from the far East, and a branch of the race known to Chinese historians as the Hiung-no, they emerge into history in the sixth century, then assuming the name of Turk, which they were to make famous. In the latter half of that century they became known to the rulers of Constantinople. In 568 embassies came to the Emperor from the Northern Turks. Eight years later an embassy was sent to the Southern Turks. At the very end of the century an embassy came to the Emperor Maurice in 598 from the Khan of the Turks, now claiming to be a great sovereign. But it was more than six centuries before the Empire came face to face with the actual tribe which should found the power that was to take its place. Pressed hard by the Seljuks, with territories limited to the Bithynian province, it was not till the beginning of the fourteenth century that Osman, the founder of the Osmanlis, came forward as a leader who should begin a line of mighty sovereigns.