578 THE TURFAN TERRITORY [Chap. XVII
success of this expedition.35 The town of Tien-ti (f it, by which probably Kao-ch`ang, i. e.
Kara-khôja, is meant,36 was quickly taken by a surprise attack. Ch`ü Chih-shêng a, who
had succeeded his father on the throne, was invested in the capital, and soon surrendered, after showers of stones thrown by the Chinese engines of siege had produced panic in the town.37
The whole territory was then occupied and turned into the district of Hsi chou ai 54.1, with the
Protectorate of An-hsi L1 established at its head-quarters. This Protectorate was for a short
while shifted to Kuchâ, after the first conquest of this territory in 648. But in consequence of a change of policy on the accession of the Emperor Kao-tsung, it was brought back again to Turfân in 65o and then located at Kao-ch`ang.38 The head-quarters of the newly formed Chinese district appear to have been left at the capital, i. e. Chiao-ho, the present Yâr-khoto. Not until Chinese power had been extended over the whole of the Tarim basin and the territories north of it, by a final victory over the Western Turks, was the An-hsi Protectorate transferred, A. D. 658, to its definite location at Kuchâ.
The territory secured by the taking of Chiao-ho and its king is stated to have comprised three districts, five ` sub-prefectures ', twenty-two towns, eight thousand households, thirty thousand inhabitants and four thousand horses. Whether the figures of population here given may be considered as approximately accurate it is impossible to say. The mention that in Tien-ti (Kao-ch`ang) alone more than seven thousand prisoners were taken might well suggest some under-estimate. A similar inference may be drawn from the assertion attributed to Ch`ü Wên-t`ai that if the Chinese force that got through the desert were to number less than thirty thousand men, his own army would be able to master it.39 However this may be, it is clear that the great strategic importance of Turfân was from the first fully recognized by those who prepared the Emperor T`ai-tsung's plans for the extension of Chinese supremacy into the Western countries. A sign of the special value attached by them to the possession of this foothold may be recognized in the fact that the Emperor decided upon the complete incorporation of the territory within the administrative limits of the empire, instead of allowing it to remain under a vassal chief, as was urged by memorials reproduced at length in the Tang shu, and as was done in the case of the states subsequently reduced within the Tarim basin.40
The conquest of the Turfân basin was supplemented at the same time by the occupation of the adjoining territory on the northern side of the Tien-shan. Ch`ü Wên-t`ai had relied on the help of the Western Turks, secured by a treaty with their supreme chief, and one of their Shê-hu (Jabgu) had been placed in the town of Kagan-stûpa, corresponding to the later Pei-t`ing.41 But overawed by the Chinese advance he surrendered the territory, which was turned into the Chinese district of Ting ►x.42 Thus firmly posted astride as it were of the Tien-shan, the Chinese were in safe possession of a base which secured the routes both north and south of the mountains for the farther advance, and which was capable of furnishing supplies for the forces needed to effect it.
35 Cf. above, pp. 544 sq.
36 Cf. Franke, Inschrift aus Idikutcahri, pp. 31 sqq., where evidence from Chinese historical texts is adduced that Tien-ti was the original name of the locality where the military colony of Kao-ch`ang was founded under the Han.
37 See Chavannes, Turcs occid., p. 1o6; also Notes addit., T`oung-pao, 1904, pp. 7 sq.
I believe that the great importance which the Chinese command attached to the construction of these siege engines, especially ballistae, as clearly indicated in the inscription of the Barkul pass (see Chavannes, Dix inscriptions, pp. 3o sq.), must be accounted for by the strength of the position occupied
by the capital Chiao-ho or Yâr-khoto.
The site, as the plan Pl. 35 shows, is defended on all sides by the high and precipitous loess cliffs of the two ` Yars ' between which the town was built. The great strength of the walls and fosse thus provided by Nature would have made direct assault very difficult and a siege without artillery necessarily protracted.
38 See Chavannes, Turcs occid., p. 1o7, note r, with the rectification in T'oung-pao, 1904, p. 19.
39 See ibid., p. 1o6.
40 See ibid., pp. 107 sq. 41 Cf. above, pp. 555 sq.
42 See Chavannes, Turcs occid., p. 109.