subjects, he left them alone. There is no record of their conversion, which probably ensued in course of time; but they can hardly be identified with the group of ten thousand tents of infidel Turks who embraced Islam in the following year, as these latter are expressly stated to have harried and plundered the Musalmans before their conversion. [721] The invasion of the Qarā Khitāy into Turkistan [722] dealt a severe blow to the power of Islam, and as late as the thirteenth century the reports of European travellers show that there were still important groups of Buddhists, Manichæans and Christians in these parts. [723] Of supreme importance to Islam was the conversion of the Saljūq Turks, but no record of their conversion remains beyond the statement that in A.D. 956 Saljūq migrated from Turkistan with his clan to the province of Bukhārā, where he and his people enthusiastically embraced Islam. [724] This was the origin of the famous Saljūq Turks, whose wars and conquests revived the fading glory of the Muhammadan arms and united into one empire the Muslim kingdoms of Western Asia. When at the close of the twelfth century, the Saljūq empire had lost all power except in Asia Minor, and when Muḥammad Ghūrī was extending his empire from Khurāsān eastward across the north of India, there was a great revival of the Muslim faith among the Afghāns and their country was overrun by Arab preachers and converts from India, who set about the task of proselytising with remarkable energy and boldness. [725] The traditions of the Afghāns represent Islam as having been peaceably introduced among them. They say that in the first century of the Hijrah they occupied the Ghūr country to the east of Herāt, and that Khālid b. Walīd came to them there with the tidings of Islam and invited them to join the standard of the Prophet; he returned to Muḥammad accompanied by a deputation of six or seven representative men of the Afghan people, with their followers, and these, when they went back to their own country, set to work to convert their fellow-tribesmen. [726] This tradition is, however, devoid of any historical foundation, and the earliest authentic record of conversion to Islam from among the Afghans seems to be that of a king of Kābul in the reign of al-Maʼmūn. [727] His successors, however, seem to have relapsed to Buddhism, for when Yaʻqūb b. Layth, the founder of the Ṣaffārid dynasty, extended his conquests as far as Kābul in 871, he found the ruler of the land to be an “idolater,” and Kābul now became really Muhammadan for the first time, the Afghans probably being quite willing to take service in the army of so redoubtable a conqueror as Yaʻqūb b. Layth, [728] but it was not until after the conquests of Sabaktigīn and Maḥmūd of Ghazna that Islam became established throughout Afghanistan. Of the further history of Islam in Persia and Central Asia some details will be found in the following chapter. CHAPTER VIII.