Sec. ii] THE HISTORICAL ROLE OF HAMI 1149
historical times either by climatic changes or by those diversions to which river-courses are peculiarly liable in deltaic regions. On the other hand, Hami must at all times have been particularly exposed to hostile inroads from the north. The ground along the whole north slope of this portion of the Tien-shan, being subject to a much less arid climate, affords plentiful grazing, as I was able to realize fully on my passage to Bar-kul and Guchen in 1914. It must for this reason always have attracted nomads and facilitated raiding exploits. Abundant evidence in the Chinese historical records of Han and Tang times shows how strong and prolonged the hold of the Huns and their nomad successors was upon this ground.. Passes practicable at all seasons, both to the east and to the west of the Karlik-tagh, give ready access from the north to the plain of Hami and, no doubt, greatly facilitated raids. Thus from the Bar-kul-dawân (Map No. 72. c. 3), which is easy enough to be crossed by carts, the central oasis can be reached in a single day's ride.
This constant liability to northern attack, from which Hami has suffered whenever Chinese power in Central Asia weakened, is fully illustrated by its chequered history, as recorded in the Chinese Annals, and right down to our own times. To follow in detail these péripéties in the fate of I-wu•, as Hâmi was known to the Chinese from Han to T'ang times, does not come within the scope of my task here.' As regards the former period, it will suffice to point out that within four years of the first establishment of a Chinese military colony in A. D. 73 I-wu was lost again to the Hsiung-nu ; 8 reoccupied between A.D. 90-104, it suffered once more the same fate.3 The notice concerning the re-establishment of a military colony there in A. D. 131 brings out clearly the strategic value which the Chinese rightly attached to Hami.1° But obviously their hold upon it ceased when imperial control over the ' Western regions ' was abandoned after the middle of the second century. The submission of Hâmi to the last Emperor of the Sui dynasty, in A.D. 6o8, proved equally short-lived, the Western Turks soon recovering their hold upon it.11 But when the great Tang Emperor Tai-tsung about A.D. 63o commenced those operations against the Western Turks which within twenty years led to the extension of Chinese political control over the whole of Eastern Turkestan and even beyond, we find the chief of Hami among the very first to seek protection under the Empire.12
We know little or nothing as to how Hâmi fared during the troubled times of the eighth century when the Turks from the north and the Tibetans from the south were ever threatening, and at last completely severed, the communications between China and the Western countries it endeavoured to ' p'rotect'. But when, nearly a thousand years later, the extension of Chinese power into Central Asia was started afresh by the Emperor K'ang-hsi's operations against the Dzungars, Hâmi once again suffered much in its accustomed rôle as an advanced base contested by both powers.'s How
Hâmi exposed to inroads from north.
Hami from Later Han to Tang times.
Hami since Chinese reconquest of Turkestan.
7 For a comprehensive account of the history of Hâmi, particularly useful from the Mongol period onwards, see Imbault-I-Iuart, Le pays de Rami ou Khamil, pp. 28 sqq. For the earlier epochs more exact information has since been made accessible through M. Chavannes' translations in Les pays 'occidenl d'après le Reou Han Chou (T'oungpao, 1907, pp. 156 sqq.) and '!'arcs occid., pp. 169 sq. and passim (see Index). Ritter had clearly realized the historical importance of Hami, and the full analysis of the notices available to him, given in Asien, ii. pp. 357-8, can still be referred to with profit.
8 Cf. Chavannes, T'oung-pao, 1907, pp. 156, 158. 8 See Chavannes, ibid., pp. 158, 16o.
1° Cf. Chavannes, ibid., p. 167 ; the advantage which the I-Isiung-nu derived from Hami in making their predatory in
roads is specially referred to.
The notice of the Later Han Annals (Chavannes, T'oungpao, p. 169), describing the northern route which passed I-wu, enumerates the products of Hâmi and emphasizes the fertility of its soil, like that of the Turfän depression. ' That is why the Han have constantly disputed Chit-shih (the present territories of Turfan and Guchen) and I-wu with the Hsiungnu in order to dominate the Western countries.'
" Cf. Chavannes, T'oung-pao, 1907, pp. 169 sq.; see also Imbault-Huart, Le pays de 'Hami ou Khamil, p. 31.
12 Cf. Chavannes, T'oung-pao, 1907, p. 170; ImbaultHuart, loc. cil., p. 32.
13 See Imbault-Huart, ibid., pp. 44 sqq. ; Ritter, Asien, ii. pp. 37o sq.