The national line of policy of the Hsiung-nu did not at all mean an end
of hostilities and raids on Chinese territory, so that Kao Tsu declared
himself ready to give the Hsiung-nu the foodstuffs and clothing
materials they needed if they would make an end of their raids. A treaty
to this effect was concluded, and sealed by the marriage of a Chinese
princess with Mao Tun. This was the first international treaty in the
Far East between two independent powers mutually recognized as equals,
and the forms of international diplomacy developed in this time remained
the standard forms for the next thousand years. The agreement was
renewed at the accession of each new ruler, but was never adhered to
entirely by either side. The needs of the Hsiung-nu increased with the
expansion of their empire and the growing luxury of their court; the
Chinese, on the other hand, wanted to give as little as possible, and no
doubt they did all they could to cheat the Hsiung-nu. Thus, in spite of
the treaties the Hsiung-nu raids went on. With China's progressive
consolidation, the voluntary immigration of Chinese into the Hsiung-nu
empire came to an end, and the Hsiung-nu actually began to kidnap
Chinese subjects. These were the main features of the relations between
Chinese and Hsiung-nu almost until 100 B.C.

In the extreme south, around the present-day Canton, another independent
empire had been formed in the years of transition, under the leadership
of a Chinese. The narrow basis of this realm was no doubt provided by
the trading colonies, but the indigenous population of Yüeh tribes was
insufficiently civilized for the building up of a state that could have
maintained itself against China. Kao Tsu sent a diplomatic mission to
the ruler of this state, and invited him to place himself under Chinese
suzerainty (196 B.C.). The ruler realized that he could offer no serious
resistance, while the existing circumstances guaranteed him virtual
independence and he yielded to Kao Tsu without a struggle.