Another line of Chinese rulers, bearing the family name of Ch’iu, established themselves at Kao-ch’ang in 507 and under the Sui dynasty one of them married a Chinese princess.  Turfan paid due homage to the T’ang dynasty on its accession but later it was found that tributary missions coming from the west to the Chinese court were stopped there and the close relations of its king with the western Turks inspired alarm.  Accordingly it was destroyed by the imperial forces in 640.  This is confirmed by the record of Hsuan Chuang.  In his biography there is a description of his reception by the king of Kao-ch’ang on his outward journey.  But in the account of his travels written after his return he speaks of the city as no longer existent.

Nevertheless the political and intellectual life of the oasis was not annihilated.  It was conquered by the Uigurs at an uncertain date, but they were established there in the eighth and ninth centuries and about 750 their Khan adopted Manichaeism as the state religion.  The many manuscripts in Sogdian and other Persian dialects found at Turfan show that it had an old and close connection with the west.  It is even possible that Mani may have preached there himself but it does not appear that his teaching became influential until about 700 A.D.  The presence of Nestorianism is also attested.  Tibetan influence too must have affected Turfan in the eighth and ninth centuries for many Tibetan documents have been found there although it seems to have been outside the political sphere of Tibet.  About 843 this Uigur Kingdom was destroyed by the Kirghiz.

Perhaps the massacres of Buddhist priests, clearly indicated by vaults filled with skeletons still wearing fragments of the monastic robe, occurred in this period.  But Buddhism was not extinguished and lingered here longer than in other parts of the Tarim basin.  Even in 1420 the people of Turfan were Buddhists and the Ming Annals say that at Huo-chou (or Kara-Khojo) there were more Buddhist temples than dwelling houses.

Let us now turn to Khotan.[508] This was the ancient as well as the modern name of the principal city in the southern part of the Tarim basin but was modified in Chinese to Yu-t’ien, in Sanskrit to Kustana.[509] The Tibetan equivalent is Li-yul, the land of Li, but no explanation of this designation is forthcoming.

Traditions respecting the origin of Khotan are preserved in the travels of Hsuan Chuang and also in the Tibetan scriptures, some of which are expressly said to be translations from the language of Li.  These traditions are popular legends but they agree in essentials and appear to contain a kernel of important truth namely that Khotan was founded by two streams of colonization coming from China and from India,[510] the latter being somehow connected with Asoka.  It is remarkable that the introduction of Buddhism is attributed not to these original colonists but to a later missionary who, according to Hsuan Chuang, came from Kashmir.[511]