The collapse of the Han dynasty in 220 ce had serious repercussions in China and Inner Asia. Most important, it left China divided into several independent states for the first time since the Eastern Zhou period (771-221 bce). The northern Chinese states during this period of disunion (220-589), like much of Europe after the fall of the Western Roman Empire, came under the control and influence of various wandering, raiding peoples. The southern Chinese states, although much more securely preserving the cultural legacy of the Han dynasty, were eventually conquered by the north in the sixth century ce. The result was a tension between the two regions of China and between China and its nomadic neighbors that characterized the entire period from the fall of the Han into the 1100s.
The Tang dynasty (618-907) mostly succeeded in controlling the nomadic threat; throughout the Northern Song dynasty (960-1135), the nomadic peoples had the upper hand. Chinese society changed in connection with this armed conflict: At the beginning of this period, military matters and warriors played prominent roles in Chinese society. By the twelfth century, these roles had been reduced significantly, and Chinese society had been decisively civilianized.