In China's history, the political power established by the agricultural peoples generally did not exceed the dividing line between agriculture and animal husbandry at that time. Even if the pastoral areas are occupied, most of them are unable to consolidate and accept the nomads.

In China's history, the political power established by the agricultural peoples generally did not exceed the dividing line between agriculture and animal husbandry at that time. Even if the pastoral areas are occupied, most of them are unable to consolidate and accept the nomads, and eventually they have to be transformed into agricultural peoples.

On the contrary, the living conditions of the pastoral peoples have a low starting point and have infinite potential for upward mobility. Agrarian peoples cannot live in pastoral areas, but pastoral peoples can live in agricultural areas at all. Therefore, there have been many incidents in history of the southern invasion of the northern herdsmen and even the complete reunification of China, but there are few examples of the northern expedition of the southern agricultural peoples crossing the Yinshan and Yanshan Mountains to achieve reunification.