region of the present
Nanking, the Wu dynasty.

The situation of the southern kingdom of Shu Han (221-263) corresponded
more or less to that of the Chungking regime in the Second World War.
West of it the high Tibetan mountains towered up; there was very little
reason to fear any major attack from that direction. In the north and
east the realm was also protected by difficult mountain country. The
south lay relatively open, but at that time there were few Chinese
living there, but only natives with a relatively low civilization. The
kingdom could only be seriously attacked from two corners--through the
north-west, where there was a negotiable plateau, between the Ch'in-ling
mountains in the north and the Tibetan mountains in the west, a plateau
inhabited by fairly highly developed Tibetan tribes; and secondly
through the south-east corner, where it would be possible to penetrate
up the Yangtze. There was in fact incessant fighting at both these
dangerous corners.

Economically, Shu Han was not in a bad position. The country had long
been part of the Chinese wheat lands, and had a fairly large Chinese
peasant population in the well irrigated plain of Ch'engtu. There was
also a wealthy merchant class, supplying grain to the surrounding
mountain peoples and buying medicaments and other profitable Tibetan
products. And there were trade routes from here through the present
province of Yuennan to India.

Shu Han's difficulty was that its population was not large enough to be
able to stand against the northern State of Wei; moreover, it was
difficult to carry out an offensive from Shu Han, though the country
could defend itself well. The first attempt to find a remedy was a
campaign against the native tribes of the present Yuennan. The purpose of
this was to secure manpower for the army and also slaves for sale; for
the south-west had for centuries been a main source for traffic in
slaves. Finally it was hoped to gain control over the trade to India.
All these things were intended to strengthen Shu Han internally, but in
spite of certain military successes they produced no practical result,
as the Chinese were unable in the long run to endure the climate or to
hold out against the guerrilla tactics of the natives. Shu Han tried to
buy the assistance of the Tibetans and with their aid to carry out a
decisive attack on Wei, whose dynastic legitimacy was not recognized by
Shu Han. The ruler of Shu Han claimed to be a member o