Disunion after the Han Dynatsy
From the 2nd to the 6th century, China went through a period of disunity. The disintegration began with the displacement of the Eastern Han by three regimes, the Wei, Shu and Wu. One of China's most famous literary epics, The Romance of the Three Kingdoms, which was written by Luo Guanzhong during the Ming dynasty, is a fictionalised account of this period.
Numerous petty kingdoms rose and fell during this time. Groups of northern "barbarians" made inroads into China during this time, establishing a series of kingdoms in the vulnerable north. Eventually the Tuoba tribe of the Xianbei unified northern China and established the Northern Wei dynasty.
Xiao Wendi, an emperor of the Northern Wei dynasty, carried out a series of reforms, basing his kingdom along the Chinese bureaucracy. The Confucian bureaucracy would prove to be one of China's most durable institutions & by adopting it, would be rulers could gain legitimacy and claim the "Mandate of Heaven," whether they were ethnic Chinese or not. This extended period of northern incursion into Chinese lands saw the intermingling of different ethnic groups and exchange of knowledge.
It was during Han dynasty when Buddhism first came to China from India. Temples and stupas, the architecture that people associate with Chinese Buddhism began to sprout throughout the land. As a sign of devotion, Buddhist cave carvings began to be made in northern China. The ones at Yungang and Longmen continue to awe and inspire visitors.
There were mass migrations during this period of upheaval. Some were by those seeking a better future, while others were forced from their homes. Vast numbers of Han Chinese journeyed south, expanding the cultural boundaries of China. They brought new technologies and Han culture as they moved into the periphery and assimilated or displaced the local population.