the southwest 261in Kan-su (Chiu T’ang shu 197:7a; Wen-hsien t’ung-k’ao 329:70b).
In 750, Nan-chao and China had their first military encounter. The
Grand Administrator of Yün-nan commandery, southeast of Nan-chao,
abused and insulted Ko-lo-feng, whereupon the latter attacked and
killed him (Chiu T’ang shu 197:7a-7b).
In 751, Hsüan-tsung ordered the Military Commissioner of Chien-
nan, whose territory adjoined Nan-chao north of the Yangtze, to lead
troops against Ko-lo-feng. Ko-lo-feng sent envoys to offer peace and
promised the return of the Chinese prisoners he had taken. He also
pointed out that Yün-nan did not belong to the T’ang, and that great
bodies of Tibetan troops were standing at his northern border. Unless
the Chinese withdrew their armies, he would be forced to ally himself
with Tibet. This was rejected by Hsüan-tsung, and the envoys were
detained. The war continued and turned into a military and diplo-
matic disaster for the Chinese. Their armies were utterly defeated,
and Ko-lo-feng allied himself with the Tibetans. These conferred on
him the Tibetan name for king, also called him the Eastern Emperor,
and presented him with a golden seal. A second Chinese attack in
753 ended in another great defeat (Chiu T’ang shu 197:7b; Wen-hsien
t’ung-k’ao 329:70b).
When An Lu-shan rose in 755, Ko-lo-feng took advantage of the
opportunity and conquered Sui commandery, situated northwest of
Nan-chao east of the upper course of the Yangtze. He there captured
the Prefect of Hsi-lu,^38 Cheng Hui, who held the degree of Understand-
ing the Classics. Ko-lo-feng came to respect him highly and made him
the tutor of his son Feng-chia-yi (Chiu T’ang shu 197:7b-8a; Wen-hsien
t’ung-k’ao 329:71a).
Ko-lo-feng died in 778 and, since his son Feng-chia-yi had preceded
him, was succeeded by the latter’s son Yi-mou-hsün. Cheng Hui was
kept at the court and ordered to tutor the sons of Yi-mou-hsün (Chiu
T’ang shu197:7b;Wen-hsien t’ung-k’ao 329:71a).
Yi-mou-hsün greatly expanded his state to comprise all what now
is Yün-nan province and used from 787 Ta-li as his capital.
Displeased with his Tibetan alliance and supposedly influenced by
Cheng Hui, Yi-mou-hsün decided to seek a reprochement with China.
He secretly sent three envoys to Ch’ang-an, where Te-tsung received
(^38) Situated 25 li W of the present Hsi-ch’ang hsien, Ssu-ch’uan.