2 _Turkish policy_

The foreign policy of this first period of the T'ang, lasting until
about 690, was mainly concerned with the Turks and Turkestan. There were
still two Turkish realms in the Far East, both of considerable strength
but in keen rivalry with each other. The T'ang had come into power with
the aid of the eastern Turks, but they admitted the leader of the
western Turks to their court; he had been at Ch'ang-an in the time of
the Sui. He was murdered, however, by Chinese at the instigation of the
eastern Turks. The next khan of the eastern Turks nevertheless turned
against the T'ang, and gave his support to a still surviving pretender
to the throne representing the Sui dynasty; the khan contended that the
old alliance of the eastern Turks had been with the Sui and not with the
T'ang. The T'ang therefore tried to come to terms once more with the
western Turks, who had been affronted by the assassination; but the
negotiations came to nothing in face of an approach made by the eastern
Turks to the western, and of the distrust of the Chinese with which all
the Turks were filled. About 624 there were strong Turkish invasions,
carried right up to the capital. Suddenly, however, for reasons not
disclosed by the Chinese sources, the Turks withdrew, and the T'ang were
able to conclude a fairly honourable peace. This was the time of the
maximum power of the eastern Turks. Shortly afterwards disturbances
broke out (627), under the leadership of Turkish Uighurs and their
allies. The Chinese took advantage of these disturbances, and in a great
campaign in 629-30 succeeded in overthrowing the eastern Turks; the khan
was taken to the imperial court in Ch'ang-an, and the Chinese emperor
made himself "Heavenly Khan" of the Turks. In spite of the protest of
many of the ministers, who pointed to the result of the settlement
policy of the Later Han dynasty, the eastern Turks were settled in the
bend of the upper Hwang-ho and placed more or less under the