precluded even a thought of the barbarians in the four quarters of the world. Those even who [before] had never ceased to be in relations with China, became barely known by name, and nothing was learned of the commencement and end of the reigns of their princes.' 1 We know that Tibetan predominance replaced Chinese control throughout the Tarim Basin from the close of the eighth century, but there is nothing to give light as to the manner and extent in which it asserted itself generally, or how it affected Khotan.
The rising power of the U igurs appears from about 86o A. D. onwards to have gradually pressed the Tibetans southwards, and to have established itself in their place in the north-eastern part of the Tarim Basin. But the kingdom founded by the Uigur 'with its main seat about Turfan and Urumchi, did not extend westwards beyond Kucha, a>!id certainly stopped short of the
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limits of Khotan 2. There is nothing to indicate that the latter had lost its local dynasty during the period of Tibetan ascendancy, and it is likely that the latter was checked and balanced to some extent by the activity of the Turkish tribes holding the valleys and plateaus of the Tien-shan, whom the Chinese rule had controlled but never completely enfeebled. Whatever degree of independence Khotan retained during this period, it is certain that Tibetan encroachments succeeded in raising an effective barrier to any direct intercourse between its rulers and the Chinese court until the year 938.
It was then that the arrival of an embassy with presents from Khotan was again recorded by the Annalists of the ' Five Dynasties '. In response the emperor Kao tsu, of the Posterior Han Dynasty, granted to Li Shêng-t`ien, the ruler of Khotan, the title of king, and dispatched a mission composed of Chang Ktuang-yeh, Kao Chü-hui, and some other officers, to notify to him this imperial favour. The account of this mission, as reproduced by the Pien i lien, is a document of considerable geographical and historical interest 3. The detailed way in which the route followed through Kan-chou, Su-chou, Sha-chou, and then through the desert to the eastern confines of Khotan territory is there described, shows best, perhaps, how completely this great line of communication, once the high road from China to its Central Asian dominions, had fallen into oblivion during the preceding two centuries. This is not the place to examine the valuable topographical and ethnographic data which the report of Kao Chü-hui furnishes'. It must suffice to mention that the mission from Ling-chou, on the Huang-ho, up to the frontiers of Yü-t`ien found everywhere from place to place Tibetan tribes and encampments, and the people of Yü-t`ien engaged in a constant struggle against the Tibetans b. The great change which had taken place in the communications between China and Khotan since the time of the early Tangs is illustrated also by the time which the mission took to effect its object. Two years were spent on the journey to Khotan, and having started about the close of 938 the party did not return until 942 A. D. 8 The slowness of this progress, due, no doubt, to unfavourable local conditions, will be appreciated if the fact is recalled that in 644-645 it had taken the messenger dispatched by Hsüan-tsang to the imperial court at Hsi-an-fu only seven or eight months to return to Khotan with the emperor's reply 7.
It was, no doubt, the hope of securing help against the Tibetans which had induced the Khotan ruler to revive the old allegiance of his state to China. Accordingly, Chang K`uang-yeh
' Compare Ville de Khotan, p. 74.
' Compare Grenard, Mission D. de Rhins, ii. pp. 47, 49.
3 See Rémusat, Ville de Khotan, pp. 74-81.
4 For earlier analyses, compare Ritter, Asien, i. pp. 212 sqq.; v pp. 375 sqq.; Richthofen, China, i. p. 536. a Ville de Khotan, p. 81.
a See Ville de Khotan, p. 75. (The seventh year there named is, no doubt, that of the regnal period Tien fu (936944 A. D.), not the seventh year from the mission's start as assumed by Richthofen, China, i. p. 536.)
7 See Vie de H-T., pp. 285, 288.