Secondly, Khwaja-Ishan worship prevailed. The Khwaja family enjoyed the status of Ishan, while Ishan bore the identity of Khwaja. Due to the vigorous support of the Khwaja family, Ishan obtained full development in Xinjiang and received much more secular power and allowed Islam to penetrate into all aspects of the Uighurs‘ social life as a result. In the 15th-17th century, Ishan became the main pillar of the serf system practiced in the Uighur region. As the main content of Khwaja-Ishan worship, building and worshiping Mazar (mausoleum) prevailed here. Xinjiang is well known in the Islamic world for its Mazars witha wide coverage, large number and amazing diversity, and also for the mystical legends of the buried and the complicated content of Mazar worship. Khwaja-Ishan combined saint worship with Mazar worship, making Mazar a shrine and an important religious site. However, the real reason why they did this was simply to induce believers to pay stronger worship to the living Khwaja- Ishan and achieve their actual economic and political interests. It was in these circumstances that Khwaja-Ishan power was secularized and feudalized.
Thirdly, religious education achieved unprecedented development. Early in the 10th century, the first Islamic institution of higher learning in Chinese Islamic history was set up in Kashgar. In subsequent dynasties, 10 Islamic institutes were built and some older historic institutes were renovated. These institutes were of considerable scale, offering courses such as Arabic, Persian, Qur"anic annotation, dogmatics, Islamic Law, Islamic history, logic, Arabic grammar, poems of Sufism and works of Islamic philosophers. A large number of religious professionals and literary talents were produced in these institutes and the influence of Islam continued to expand as a result.
During this period of time, the King of Hami and his family practiced temporal-religious administration over the UighurMuslims within his territory, similar to that of khans and Khwaja- Ishan regime.
After Tuhiru Timur and his 160,000 Mongol subjects embraced Islam, all the khans after him were Muslim. They forcibly ejected other religions out of Turufan and Islam occupied the spiritual world of the Uighurs. By the early 16th century, Islam had taken the predominant position in Hami, symbolizing that the entire nation of the Uighurs in Xinjiang had by then embraced Islam. After the mid and late Ming Dynasty period, peoples such as the Kazaks to the north of Tianshan Mountain accepted Islam one after another.
The two systems of Islam in China (Islam in the inland with the Huis as representative, and Islam in Xinjiang with the Uighurs as representative) differed considerably from each other during this early period. Until the mid and late Qing Dynasty, as the policy of separating religion from politics was put into practice, the two systems tended to develop in pace with each other. As many Huis moved to Xinjiang as garrison troops or migrants, and economic contacts between the farming area in south Xinjiang and the pasturing area in north Xinjiang became closer, their economy tended to grow at the same pace. As Islam itself changed and religion became separated from politics, the functionof Shariah (Islamic law) changed as well. As Khwaja-Ishan power declined, the differences between major sects vanished, and peoples such as the Uighurs became Muslims, the two systems of Islam in China tended to be identical in pattern of sects in the early 20th century.
Of course, Islam in both Xinjiang and the inland will continue to develop in ways of their own, so far as the influence of comparatively stable factors such as ethnic background and geography is concerned.