Sec. iii] EASTERN TURKESTAN UNDER THE TANGS 61
latter's power to enforce it. In this light it can in no way surprise us to find, from the Tang Annals, that embassies from Kashgar as well as from the other states of Eastern Turkestan reached the Imperial court, with what Chinese historiographers were probably justified in recording as offers of submission, long before Chinese supremacy was actually extended over the whole of those regions. The notice on Su-lé contained in the Tang Annals mentions the first embassy of the king of Kashgar in the year 635, and a second, bringing products of the country as tokens of submission, in 639 21. We may safely recognize in the date of the earlier mission, and in the dates recorded for the first embassies from other states of Eastern Turkestan, a proof of the deep and widespread impression which the Chinese triumph over the Northern Turks in 63o A. D. and the simultaneous disruption of the Western tribes must have produced among the tributaries of the latter 22.
Chinese authority over Kashgar and the rest of the ` Four Garrisons ' was destined soon to undergo severe checks. Already in the year 662 a rebellion broke out among the Western Turks, and a Chinese army sent to repress it, while marching to the south of Kashgar, suffered humiliation at the hands of a force of the Tibetans whom the Kung-yüeh, a northern tribe from the Ili region, had incited to invasion 23. The Tibetans who, after their conquest of the Kuku-Nor region (663 A. D.), rapidly rose to be formidable rivals of the Chinese power in Central Asia, availed themselves of the difficulties caused to the latter by the internal dissensions of the Turkish tribes and their successive defection. Urged on by the Kung-yüeh and the ruler of Kashgar, they attacked, in the year 665, Khotan which had to be relieved by Chinese troops 24.
After a terrible defeat inflicted on the Imperial forces in 670 A. D., north of the Kuku-Nor, the Tibetans were free to make themselves masters of the ` Four Garrisons 25. It is true, a Chinese record tells us of the Kung-yüeh and the king of Su-lé, frightened by the approach of an Imperial army, having offered their submission in the year 673 26. But this success can only have been ephemeral ; for the plain statements of the Tang Annals show that the Tibetans completely subjected Kashgar during the years 676-678, and in fact retained possession of the whole of the ` Four Garrisons ' from that time until 692 27. In that year a victorious expedition under the Chinese general Wang Hsiao-chieh re-established the Protectorate of An-hsi at Kucha, and by maintaining there a garrison of thirty thousand men recovered once more the territories previously subject to it 28.
For more than half a century after this re-conquest the ` Four Garrisons ' served as the base from which the Chinese endeavoured to assert their influence over the territories to the west and south-west. In these endeavours they had to face two powerful enemies, the Arabs in the west and the Tibetans in the south, and the success with which on the whole this double struggle was maintained during the reign of the Emperor Hsüan-tsung (713-762 A. D.) renders this period one of great historical interest. M. Chavannes, whose merit it is to have first rendered accessible and elucidated the ample Chinese accounts referring to this period, has
41 See Chavannes, Turcs occid., pp. 12x sq., where the Notice on Su-16 has been translated from chap. ccxxi. of the
" According to the testimony of the Tang Annals, the first embassy from Kara-shahr (Yen-chi) arrived in 632 A.D., from Khotan (Yü-t`ien) in 632, from Sarikol (Ho-Van-Co) in 635, from Chu-chü-po (Karghalik) in 639 ; see Chavannes, ibid., pp. 11 r, 126, 125, 121, resp. Turfan (Kao-ch`ang) and Kuchâ (Ch`iu-tzû), whose royal families appear to have been
more closely connected with China, had already sent missions after the accession of Kao-tsu (618 A.D.), and hastened to give fresh evidence of their devotion in 63o ; comp. Chavannes, Turcs occid., pp. 103, 115.
" Compare Chavannes, ibid., pp. 122, note, 280.
u See ibid., p. 122, note.
" See ibid., pp. "4, note, 28o sq.
26 See ibid., p. 122, note. n Comp. ibid., pp. 119, 122.
28 Compare ibid., pp. 119, 179 note.
First irruptions of Tibetans, 662-692
Chinese struggle against Arabs and Tibetans.