~~TThe Southern and Northern Dynasties (420-589) followed the Sixteen Kingdoms and preceded Sui Dynasty in China and was an age of civil wars and disunity.

During this period the process of sinicization accelerated among the non-Chinese arrivals in the north and among the aboriginal tribesmen in the south. Many northern Chinese also immigranted to the south. This process was also accompanied by the increasing popularity of Buddhism (introduced into China in the first century A.D.) in both north and south China.

The south and north developed into a relatively stable equilibrium, due to geographical differences. The flat steppes of the north gave a significant edge to cavalry, while the riverlands of the south gave a significant edge to naval warfare. A strong navy on the Yangtze River could protect the south from the north, since cavalry was useless in the riverlands. Likewise, logistics difficulties for the horse-poor south made it difficult to maintain a successful northern campaign. Depending on the relative strengths of the states, the Huai River area and the Sichuan basin were the primary areas of significant territorial changes. This barrier was only overcome by the first emperor of the Sui Dynasty, who built a large invading navy in the Sichuan basin.