The 7th century seems to have been notable in the religious history of China. Early in that century, Mazdaism, or the religion of Zoroaster, based upon the worship of fire, was introduced into China, and in 621 the first temple under that denomination was built at Ch'ang-an in Shensi, then the capital. But the harvest of converts was insignificant; the religion failed to hold its ground, and in the 9th century disappeared altogether.
Mahommedans first settled in China in the Year of the Mission, A.D. 628, under Wahb-Abi-Kabha, a maternal uncle of Mahomet, who was sent with presents to the emperor. Wahb-Abi-Kabha travelled by sea to Canton, and thence overland to Ch'ang-an, the capital, where he was well received. The first mosque was built at Canton, where after several restorations, it still exists. Another mosque was erected in 742; but many of the Mahommedans went to China merely as traders, and afterwards returned to their own country. The true stock of the present Chinese Mahommedans was a small army of 4000 Arab soldiers sent by the caliph Abu Giafar[14] in 755 to aid in putting down a rebellion. These soldiers had permission to settle in China, where they married native wives; and four centuries later, with the conquests of Jenghiz Khan, large numbers of Arabs penetrated into the empire and swelled the Mahommedan community. Its members are now indistinguishable from the general population; they are under no civic disabilities, and are free to open mosques wherever they please, so long as, in common with Buddhists and Taoists, they exhibit the tablet of the emperor's sovereignty in some conspicuous position.
In A.D. 631 the Nestorians sent a mission to China and introduced Christianity under the name of the Luminous Doctrine. In 636 they were allowed to settle at Ch'ang-an; and in 638 an Imperial Decree was issued, stating that Olopun, a Nestorian priest who is casually mentioned as a Persian, had presented a form of religion which his Majesty had carefully examined and had found to be in every way satisfactory, and that it would henceforth be permissible to preach this new doctrine within the boundaries of the empire. Further, the establishment of a monastery was authorized, to be served by twenty-one priests. For more than a century after this, Nestorian Christianity seems to have flourished in China. In 781 the famous Nestorian Tablet, giving a rough outline of the object and scope of the faith, was set up at Ch'ang-an (the modern Si-gan Fu), disappearing soon afterwards in the political troubles which laid the city in ruins, to be brought to light again in 1625 by Father Semedo, S.J. The genuineness of this tablet was for many years in dispute, Voltaire, Renan, and others of lesser fame regarding it as a pious Jesuit fraud; but all doubts on the subject have now been dispelled by the exhaustive monograph of Père Havret, S.J., entitled _La Stèle de Si-ngan_. The date of the tablet seems to mark the zenith of Nestorian Christianity in China; after this date it began to decay. Marco Polo refers to it as existing in the 13th century; but then it fades out of sight, leaving scant traces in Chinese literature of ever having existed.