worship) among their gifts. As Buddhism became widely established in
China, so demand grew for such products as aromatic resins and woods
used to make incense, dyes and medicinal substances.
Buddhism, in other words, provided both a new area of common
interest and a stimulus to trade between China and Southeast Asia.
Prior to this, Chinese and Southeast Asians had had little in common.
Their worldviews, as outlined above, were far apart. For a while,
however, until the Chinese evolved their own forms of Buddhism and
the religion declined in the land of its origin, Buddhist pilgrimage
added a significant cultural dimension to relations between China and
some, at least, of the countries of the Southern Ocean.
Trade, however, still remained the primary concern. For almost
three hundred years, until China was again unified under the Sui
dynasty in 589 CE, non-Chinese dynasties ruled north China. Though
these dynasties did much to promote Buddhism, tens of thousands of
Chinese families fled south to the Yangze region and beyond to escape
their reach. This permanently shifted the balance of population and
reinforced the Chinese character of the coastal provinces south to
Guangdong. Southern dynasties centred on Nanjing tried unsuccess-
fully to recapture lost territory in the north, often to the neglect of still
only lightly sinicised regions west of Canton. Jiao-zhi (northern
Vietnam) in particular remained a frontier area, a prey to the ambitions
of independent-minded governors and raids by Cham fleets sailing up
from the central coast of Vietnam. Disruption to trade was at times
serious, until in 446 a Sino–Vietnamese expedition decisively defeated
the Cham, ushering in more than a century of peaceful relations.
An analysis of fifth and sixth century diplomatic missions from
Southeast Asia reveals a clear correlation between tribute and trade on
the one hand, and conditions in China on the other.^4 During times of
political unrest, central government control over the coastal provinces
was weak, and so was demand for luxury products. As lawlessness and
piracy increased, foreign vessels were reluctant to call at Chinese ports.
When central authority was reimposed, as it was under the Liang
Early relations