Kashgar Contemporaneously, Nestorian Christians were establishing bishoprics at Herat, Merv and Samarkand, whence they subsequently proceeded to Kashgar, and finally to China itself.... The Uyghurs employed an alphabet based upon the Syriac and borrowed from the Nestorian missionaries, but after converting to Islam widely used also an arabic script. They spoke a dialect of Turkish preserved in the Kudatku Bilik, a moral treatise composed in 1065. http://en.wikipedia.org/wiki/Kashgar