But the early history of this people and of their civilization is chiefly a matter of theory. In the Han period[507] there was a kingdom called Kü-shih or Kiü-shih, with two capitals. It was destroyed in 60 B.C. by the Chinese general Chêng-Chi and eight small principalities were formed in its place. In the fourth and fifth centuries A.D. Turfan had some connection with two ephemeral states which arose in Kansu under the names of Hou Liang and Pei Liang. The former was founded by Lü-Kuang, the general who, as related above, took Kucha. He fell foul of a tribe in his territory called Chü-ch'ü, described as belonging to the Hsiung-nu. Under their chieftain Mêng-hsün, who devoted his later years to literature and Buddhism, this tribe took a good deal of territory from the Hou Liang, in Turkestan as well as in Kansu, and called their state Pei Liang. It was conquered by the Wei dynasty in 439 and two members of the late reigning house determined to try their fortune in Turfan and ruled there successively for about twenty years. An Chou, the second of these princes, died in 480 and his fame survives because nine years after his death a temple to Maitreya was dedicated in his honour with a long inscription in Chinese. 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 Hsüan 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 Manichæism 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.