and tended, as a result, to become more complacent and inward-
looking. In short, Dali was much less prepared than was Vietnam to
counter Mongol invasion.
Once the Mongols had seized control of Yunnan, they set about
administering it as a Chinese province, under Mongol direction. As
many Mongols were then Muslim, Islam was propagated and widely
embraced, so that even today Yunnan has the second largest Muslim
population (after Xinjiang) of any province of China. Given both the
topography and ethnic diversity of Yunnan, it was relatively easy,
through a policy essentially of divide and rule imposed by military
garrisons, to maintain Chinese domination. Steady, if slow, migration
that has continued up to the present day swung the balance of popu-
lation over time in favour of the Chinese, and assisted in the process
of sinicisation.
The conquest of Yunnan altered forever the relationship between
China and Southeast Asia. Strategically it projected Chinese power
to the south and west into direct contact with kingdoms and peoples
with whom they had previously had little or no intercourse at all.
These included the Burmese, the Tai of Sukhothai and Lan Na, and
the Lao of Luang Phrabang, then known as Meuang Sua. Under threat
of military invasion, all were brought within the Chinese tributary
system, thus initiating lasting diplomatic and political relations.
At the same time, new trade routes were opened up from Yunnan
into Burma and the Tai kingdoms along which Yunnanese merchants
led their hardy mountain ponies. The Venetian traveller, Marco Polo,
may also have passed this way. While overland trade never matched
sea trade in importance, it was significant for the countries involved
and for Yunnan itself, for alternative routes east were long and diffi-
cult. As the wealth of mainland Southeast Asian kingdoms grew, so
too did trading opportunities with Yunnan, though the full potential
for trade between the two regions still remains to be realised with the
improved communications envisaged for the twenty-first century.
Mongol expansionism