The Abassides, established in the city of Bagdad, which they had founded, persecuted and tolerated the Christians by turns. The Christians, always living between the fear of persecution and the hope of a transient security, saw at last the prospect of happier days dawn upon them with the reign of Haroun al Raschid, the greatest caliph of the race of Abbas. Under this reign the glory of Charlemagne, which had reached Asia, protected the churches of the East.[9] His pious liberality relieved the indigence of the Christians of Alexandria, of Carthage, and Jerusalem. The two greatest princes of their age testified their mutual esteem by frequent embassies: they sent each other magnificent presents; and, in the friendly intercourse of two powerful monarchs, the East and the West exchanged the richest productions of their soil and their industry. The presents of Haroun created a lively surprise in the court of Charlemagne, and gave a high idea of the arts and riches of Asia. The monarch of the Franks took pleasure in showing to the envoys of the caliph the magnificence of the religious ceremonies of the Christians. Witnesses, at Aix-la-Chapelle, of several processions, in which the clergy had exhibited all their most precious ornaments, the ambassadors, on their return to Bagdad, reported that they had seen _men of gold_. There was no doubt policy in the marks of esteem which Haroun lavished upon the most powerful of the princes of the West. He was making war against the emperors of Constantinople, and might justly fear that they would interest the bravest among Christian people in their cause. The popular traditions of Byzantium foretold that the Latins would some day be the liberators of Greece; and in one of the first sieges of Constantinople by the Saracens, the report only of the arrival of the Franks had reanimated the courage of the besieged, and carried terror into the ranks of the Mussulmans. In the time of Haroun, the name of Jerusalem already exercised so powerful an influence over the Christians of the West, that it was sufficient to rouse their warlike enthusiasm, and raise armies to serve against the infidels. To take from the Franks every pretext for a religious war, which might make them embrace the cause of the Greeks, and draw them into Asia, the caliph neglected no opportunity of obtaining the friendship of Charlemagne; and caused the keys of the holy city and of the holy sepulchre[10] to be presented to him. This homage, rendered to the greatest of the Christian monarchs, was celebrated with enthusiasm in contemporary legends, which afterwards caused it to be believed that this prince had made the voyage and completed the conquest of Jerusalem.[11]