240 the southwest
by a Chancellor. On Feb.20 (the 15th day), the covenant was agreed
upon (Chiu T’ang shu 12:11a; 196B:2b-3a; Wen-hsien t’ung-k’ao 334:30b).
In this treaty, T’ang ceded territory between the upper Min and Wei
Rivers and the Yellow River to the Tibetans.
In the 2nd month (Feb./Mar.) of 784, Tibetan envoys were received
at the T’ang court, and a Grandee Secretary was sent as a Chinese
envoy in return. The latter was in the 4th month (Apr./May) followed
by the Junior Grand Master of Ceremonies and Concurrent Palace
Assistant Secretary (Chiu T’ang shu 12:14b; 196B:4b).
In the 9th month (Oct./Nov.) of 785, Te-tsung sent a General of
the Guards Inspecting the Gates of the Left as envoy to the Tibetans
in order to delineate the border (T’ang hui-yao 97:8b).
In the 10th month (Nov./Dec.) of 785, Chinese troops made a
suprise attack on the Tibetans (T’ang hui-yao 97:8b).
In 786, the T’ang court sent a Gentleman-of-the-Palace of the
Bureau of Granaries and Concurrent Grandee Secretary as an envoy
to the Tibetans. In the 8th (Aug./Sep.), 9th (Sep./Oct.), and 11th
month (Nov./Dec.) the Tibetans made deep inroads into Chinese
border lands (Chiu T’ang shu 196B:4b; T’ang hui-yao 97:9a-9b).
On Apr.5, 787, Te-tsung sent an Acting Cadet of the Left and
Concurrent Palace Assistant Secretary to the Tibetans and simul-
taneously made a military demonstration. The Tibetan Chancellor
Shan-rgyal-btsan thereupon proposed through three envoys that the
two states should conclude a covenant of peace and restore good rela-
tions. Te-tsung did not believe that the Tibetans acted in good faith
but wished peace in order to have a free hand against the Uighurs.
When the envoys repeated the request in an audience, he therefore
agreed. On May 25, the Palace Attendant Hun Chen was appointed
chief Chinese negotiator, with the Master of Writing of the Ministry
of Arms Ts’ui Han-heng as his deputy. The meeting was again to be
held at the Ch’ing River but at the request of Shan-rgyal-btsan was
moved to the P’ing-liang River, some 62 miles (100 km) northeast of
the former. On July 13, the covenant was concluded but ended in
disarray.^16 Hun Chen was robbed by the Tibetans, Ts’ui Han-heng
was temporarily arrested, and another imperial envoy was returned at
the border. In the 8th month (Sep./Oct.), Shan-rgyal-btsan sent Ts’ui
(^16) According to Chiu T’ang shu 196B:5b, it was concluded at the Ch’ing River,
which is an error for P’ing-liang River.