Tang emperors were powerful enough to demand that relations even
with the empires of the Uighurs and the Turks should conform to the
tributary system. An elaborate ceremonial was developed for escorting
envoys to the capital, welcoming them, and preparing them for the
official audience and banquet in the imperial presence. Frequent
kowtowing was expected, consisting of three kneelings and nine pros-
trations touching the forehead to the ground, symbolising submission
to the Son of Heaven.
The early Tang could demand such submission, before the
dynasty was weakened by rebellion in the mid-eighth century. Even
thereafter the formalities were preserved, as was the status distinction
between Chinese and barbarians. Yet judged on the basis of civilisation
this distinction was becoming harder to maintain. Neighbouring king-
doms, including Korea and Japan, developed high cultures that
borrowed much from the Tang. In Southeast Asia new and powerful
kingdoms arose. In Cambodia the Khmer kingdom of Angkor replaced
Zhenla; in southern Sumatra the new power of Srivijaya extended its
control over the Melaka and Sunda Straits and adjacent coasts; while
in Java the Sailendras created a powerful inland kingdom. All pro-
vided examples of high culture (the temples of Angkor, the Borobudur
in Java) that were different from, but hardly inferior to that of China.
Tang policy with respect to official contact and trade with South-
east Asia was benign. The two principal ports for the Nanyang trade
continued to be Canton and Long-bien near modern Hai-phong.
These were connected by inland routes north to the Tang capital, via
the Grand Canal that had been much improved to accommodate the
increased movement of goods and people. From these southern ports
Tang envoys voyaged abroad, and to them foreign missions came—
initially from Champa and Zhenla, then from further afield from
kingdoms on the Malay Peninsula, Sumatra and Java.
Diplomatic missions even arrived from India and Sri Lanka, indi-
cating the importance of Indians, Persians, and Arabs in the expansion
of Indian Ocean trade. Their well constructed and seaworthy ships
Early relations