the southwest 237retary, Li Chih-fang, and the Cadet of the Left and Concurrent Palace
Assistant Secretary, Ts’ui Lun, as envoys to the Tibetans. When they
reached the border, they were detained by the Tibetans (Chiu T’ang
shu 196A:12b). The reason was that the Tibetans were preparing for
a huge attack on China.
On Nov.18, 763, remarkably it happened that the Tibetans took
the T’ang capital of Ch’ang-an. They there enthroned the king of
Kuang-wu, Li Ch’eng-hung, as emperor. He was a great-grandson
of Emperor Kao-tsung, and no doubt was chosen because he was
a brother of the Princess of Chin-ch’eng. But the Tibetans had no
way of holding on to the city. They looted it for fifteen days and
then withdrew, whereupon Tai-tsung was able to return to his capital.
Ch’eng-hung, who probably had been coerced by the Tibetans, was
banished but not executed (Hsin T’ang shu 81:5a; Tzu-chih t’ung-chien
pp.7151-7153, 7157; Wen-hsien t’ung-k’ao 334:30a).
In 764, the Tibetans released Li Chih-fang and Ts’ui Lun, and in
the 3rd month (Mar./Apr.) of 765, their envoys requested peace. At
the advice of Kuo Tzu-yi, Tai-tsung accepted, and a covenant was
concluded in a Buddhist temple (Chiu T’ang shu 196A:12b; Tzu-chih
t’ung-chien p.7174; Wen-hsien t’ung-k’ao 334:30a).
War broke out again immediately, and on Oct.4, 765, a large
Tibetan army reached Feng-t’ien prefecture, situated north of the Wei
River 50 miles (80 km) northwest of Ch’ang-an (map 5). The Tibetans
advanced on Oct.5. On Oct.26, they joined forces with Uighurs and
attacked Ching-yang prefecture, situated only 27 miles (43 km) north
of Ch’ang-an. They then withdrew (Chiu T’ang shu 196A:12b; Tzu-chih
t’ung-chien pp.7177, 7180).
In the 2nd month (Mar./Apr.) of 766, Tai-tsung sent the Junior
Judge and Concurrent Palace Assistant Secretary to seek renewed
good relations with the Tibetans. These attached a mission of over
100 men, led by a chief, to the Chinese envoy to follow him back to
Ch’ang-an (Chiu T’ang shu 196B:1a).
In the 7th month (July/Aug.) of 767, Tibetan envoys were received
at the T’ang court (Ts’e-fu yüan-kuei p.5031).
In the 10th month (Oct./Nov.) of 767, Chinese troops stationed
in what now is called the Ning-hsia Oasis defeated a Tibetan army
(Chiu T’ang shu 196B:1a).
In the 11th month (Nov./Dec.) of 767, a Master of Writing of the
Ministry of Households and Concurrent Grandee Secretary returned
from a mission to the Tibetans. A Tibetan chief followed him back to