led but comprised mainly Chinese troops. Elements of the Song navy
captured by the invading Mongols formed the core of the war fleets
that projected Mongol power into maritime Southeast Asia. In attack-
ing Southeast Asia, however, Mongol forces encountered determined
resistance. The lesson learned was that armies from China could be
defeated on home territory where local forces had the advantage, but
that the tributary relationship thereafter needed to be re-established
as a security measure.
Mongol conquests
The impact of the Mongol conquest of China on the face of it threat-
ened the very basis of the Chinese worldview. This was the first time
that the entire Chinese cultural area had fallen under barbarian rule.
Mongol military might had proved superior to Chinese virtue (de). The
Chinese response was to sinicise their conquerors. The Mongols were
incorporated into Chinese history as a Chinese dynasty, the Yuan. In
this capacity, Mongol rule for almost a century had a far-reaching
impact on China’s relations with Southeast Asia: it extended Chinese
control in the southwest over a region that topographically was more
part of Southeast Asia than of China, populated overwhelmingly by
non-Chinese peoples; it projected Mongol/Chinese sea power aggres-
sively into Southeast Asia for the first time; and it demonstrated in
both these ways the potential implications for other countries of
China’s imperial view of the world.^1 Let us look at each of these.
In terms of geography, environment, population and culture,
Yunnan was, and in many ways still is, a northern extension of main-
land Southeast Asia. Much of the area is a high plateau, falling away
to the south and east. Much, too, is mountainous. Through high,
narrow valleys flow the tributaries of the great rivers that water south-
ern China and mainland Southeast Asia, none navigable on their
upper reaches. But despite the difficult terrain, merchants and pilgrims
Mongol expansionism