east turkestan 295T’ai-tsung’s change of heart was, however, brief, and he entered
into diplomatic relations with Karashahr, further west from Turfan
on the Northern Silk Route. Since Turfan greatly profited from the
caravan trade through its territory, to the detriment of travellers, the
king of Karashahr decided to bypass it and open a route through the
desert in a southeasterly direction, linking up with the Southern Silk
Route west of lake Lob-nor This was resented by Ch’ü Wen-t’ai. He
therefore attacked Karashahr in 632 and looted its territory (Tzu-chih
t’ung-chien p.6096; Wen-hsien t’ung-k’ao 336:40b).
There was no immediate reaction to this from T’ai-tsung, and mis-
sions from Turfan were received at the T’ang court in the 7th month
(Aug./Sep.) of 633 and in 634 (Chiu T’ang shu 3:3b; Ts’e-fu yüan-kuei
p.5024).
In 638, Ch’ü Wen-t’ai, allied with the Western Turks, again attacked
Karashahr, burned settlements, kidnapped men and women, and with-
drew. The king of Karashahr complained to T’ai-tsung, who sent
a Gentleman-of-the-Palace of the Bureau of Forestry to find out the
facts (Chiu T’ang shu 198:4a; Tzu-chih t’ung-chien p.6142).
T’ai-tsung had several grievances against Ch’ü Wen-t’ai, that he
had allied himself with the Western Turks, had attacked Karashar, had
threatened Hami, and had detained Chinese refugees who wished to
return to their homeland. When Turfan envoys arrived at the T’ang
court in 639, T’ai-tsung informed them that he intended to attack
their country in the following year (Chiu T’ang shu 3:6b; 198:4a; Tzu-
chih t’ung-chien 6146; Wen-hsien t’ung-k’ao 336:38b).
In the 3rd month (Apr./May) of 639, the Turkish Hsüeh-yen-t’o,
a tribe of the T’ieh-le, proposed a joint attack on Turfan. T’ai-tsung
sent a Master of Writing of the Ministry of Common People and the
General-in-chief Who Commands the Army of the Right to present
silk to the Hsüeh-yen-t’o and discuss the campaign. In the 7th month
(Aug.Sep.), he also sent the Minister of Agriculture with a letter stamped
with the imperial seal to the Hsüeh-yen-t’o (Chiu T’ang shu 198:4b;
Tzu-chih t’ung-chien pp.6146-6147, 6148).
In the 11th month (December) of 639, T’ai-tsung sent another let-
ter stamped with the imperial seal to Ch’ü Wen-t’ai, threatening him,
and summoning him to his court. Wen-t’ai refused to come under the
pretext of illness (Chiu T’ang shu198:4b;Tzu-chih t’ung-chien p.6150).
On Jan.2, 640, T’ai-tsung ordered the attack on Turfan by com-
bined Chinese and Turkish forces, over the fervent protests of Wei
Cheng and other advisers. While this army was approaching, Ch’ü