Sixty years later, Jerusalem was rebuilt by the Emperor Hadrian. He resolved to suppress altogether the troublesome and turbulent Judaism. The measures which he took caused the Jews to rise against him under Barcochebas. This was the wildest and the most bloodthirsty of all the Jewish revolts; but it was the last. Jerusalem having been recaptured, Hadrian converted it into a Roman colony, forbade Jews to approach, and built a temple of Jupiter on the site of the Temple.
It was when the Roman Emperor Constantine embraced Christianity, and his mother Helena discovered the true Cross and the Holy Places, that Jerusalem came again into prominence. Thereafter, churches and monasteries sprung up throughout Palestine, which thus, for a time, became thoroughly Christianized, under the Christian Emperors of Rome and Byzantium. But the seventh century saw the fall of the Christian ascendancy in Syria. In A.D. 614, the Persians, under Chosroes, swept through the land, massacring the Christians wholesale, and destroying most of their churches, including the Church of the Holy Sepulchre. The withdrawal of the Persians was followed by a brief return of Christian ascendancy lasting but eight years, under the Emperor Heraclius. And then, in 637, Jerusalem fell to the growing power of Islam. It was this new religion, with a calendar only dating from A.D. 622, which was to control the future destinies of the Holy City.
Islam arose at Mecca and Medina in barren and uninviting Arabia. When it started on that expansion, whereby it overspread half of the known world, Syria, from its situation, was naturally the first country to tempt its restless and devoted Arab warriors. Within ten years of the Hegira, or commencement of the Mahomedan era, we find the followers of the Prophet already in Syria. The Byzantine army was overwhelmed at the battle of the Yarmuk, and the Arabs laid siege to Jerusalem. The city capitulated to Omar, who granted terms of comparative magnanimity. His terms gave to the Christians security of person and property, safety of their churches, and non-interference on the part of Mahomedans with their religious exercises, houses or institutions. Upon the site of the Temple, which had been systematically defiled by the Christians out of abhorrence for the Jews, but which was honoured by the Moslems as the spot from which Mahomed ascended to heaven, was now erected the Mosque of Omar. This site became to the Mussulman, the most venerated spot in Jerusalem, as was the Church of the Holy Sepulchre to the Christian. When, in after years, pilgrimages to Mecca were temporarily interrupted, devout Mahomedans made the pilgrimage to Jerusalem instead.