Kao-ch’ang ［高昌国］ (PY Gaochang; Kōshō-koku): An ancient kingdom of the Turfan region of what is now the eastern part of the Sinkiang Uighur Autonomous Region in northwestern China. The Kao-ch’ang kingdom, which lasted from the fifth through the seventh century, was situated on the northern side of the Turfan Depression at the foot of the southern slope of the Tien Shan range. Buddhism prospered there from early on under the reign of the Ch’ü clan. In the early seventh century, on the way to India, the Chinese priest Hsüan-tsang was invited to visit Kao-ch’ang by the king and ruler of the Ch’ü clan, and he was accorded a hospitable welcome. Control by the Ch’ü clan lasted from 498 until 640, when T’ang-dynasty China conquered the Kao-ch’ang kingdom. Today a number of Buddhist temple ruins can be found in Karakhoja (also spelled Karakhojo) near the present-day city of Turfan. Buddhist texts written in the Uighur script and Manichaean wall paintings have been excavated there. Many caves once used as Buddhist temples also exist near Karakhoja.