Muhammed was born about 570 in Mecca, in the Arabian peninsula; a place hitherto of little importance, which had a cube-shaped sanctuary, the Kaaba, enshrining a Black Stone. It was the token or fetish of some god of nature; for some kind of nature worship, including the worship of the Sun, Moon, and Earth seems to have been the traditional religion of Arabia. Meanwhile, Judaism had penetrated into the country and Christianity had followed. Each figured in Muhammed’s imagination as a world religion. Both professed one God. One had its prophets; the other, its Messiah, and both its book of inspired revelation. Accordingly, when the vision of Muhammed embraced the idea of founding at once a new nation and a new religion, he borrowed from both Judaism and Christianity and proclaimed himself the new prophet or Messiah of the one God and made known the New Revelation, which was embodied in the Koran. The faith of Islam, as preached by Muhammed and practised by him and his followers, was essentially one of proselytising by force. “The sword,” he taught, “is the key of Heaven and Hell. A drop of blood shed in the cause of God, a night spent in arms, avails more than two months of fasting and prayer. Whoso falls in battle his sins are forgiven. At the Day of Judgment his wounds shall be resplendent with vermilion and odoriferous as musk, and the loss of limbs shall be supplied by angels’ wings.” Muhammed’s self-imposed task of subjugating and uniting Arabia for the Arabians was begun after his flight from Mecca to Medina, the celebrated _Hejira_ (Arab _hijra_) which occurred on the Jewish Day of Atonement, Sept. 30, <small>A.D.</small> 622. The further work of conquering the countries on which the Arab tribes had been dependent, Syria, Abyssinia, Persia, was continued by his followers. Of great importance in the history of architecture was the conquest of Persia (632-651), for here the Muhammedan influence developed a style that was distinguished by fine structural as well as aesthetic qualities and generally developed a beautiful revival of the various arts of decorative design. And it was Persian Muhammedan that strongly influenced the architecture of India, where Muhammedan conquest was established about <small>A.D.</small> 1000. Meanwhile, the Arabic Muhammedans had founded a dynasty under the Ommayads with its capital in Damascus and a later one under the Abassids, whose most celebrated caliph was Haroun-el-Raschid of Bagdad, made famous by the “Thousand and One Nights.” Conquest was extended westward, gradually comprising Egypt, the north of Africa, Sicily, and Spain. In 1453 the Crescent displaced the Cross in Constantinople.