In 304, the Xiongnu noble Liu Yuan set up the Han state which, in 316, vanquished the Western Jin. In 439, the Tuoba tribe of the Xianbei nationality united the north. For over a hundred years, frequent wars took place among different nationalities, resulting in the establishment of 15 states. They were the Former Zhao (Xiongnu), the Later Zhao (Jie), the Former Yan (Xianbei), the Former Liang (Han), the Former Qin (Di), the Later Qin (Qiang), the Later Yan (Xianbei), the Western Qin (Xianbei ),the Later Liang ( Di), the Southern Liang (Xianbei), the Western Liang (Han), the Northern Liang (Lushuihu), the Southern Yan (Xianbei), the Northern Yan (Han), and the Xia (Xiongnu). These fifteen states together with the Han state of Cheng established by the Di nationality in the southwest are historically called the Sixteen States.

Besides, there were five regimes：the Wei founded by Ran Min of the Han nationality； the Wei founded by the Zhai family in Dingling； the Chouchi founded by the Yang family in Wudu, a leader of the Di nationality； the Western Yan founded by the Murong family of the Xianbei nationality, and the Dai by the Tuoba family of the Xianbei nationality. There were altogether 21 states in this period.

Among them, the Later Zhao，the Former Yan and the Former Qin successively occupied most of the northern territories；especially, the Former Qin almost united the whole northern part of China.

After the Feishui Compaign，the Former Qin was shattered, thus over a century, warfare never stopped in the north.

The wholescale migration to the hinterland brought many minorities into full contacts with the Huaxia (Chinese) culture. They acquired the same tastes and conventions with Han nationality and were assimilated and accommodated in Han culture.

Since then, China was a nation embracing various ethnic groups that imbued with similar customs due to the fact that the minorities live along with the majority Han side by side in the northern part of central plain.

The rulers of Eastern Jin were contented with their sovereign in the south and did not take serious of recovering of the Central Plain.

Those landlord gentries and noble families concentrated their minds on economic developments in the south. Therefore It was possible for the nobles in the south to know the prestigious families and refugees migrated from the north in the war which enhanced the social development in the south.

Since Wei there was a prosperous development of literature,especially in the Eastern Jin Dynasty.

For example, Xie Lingyun, a landscape poem writer and Tao Yuanming , a pastoral poet grew out of the old style of poem writing and wrote the poems full of imagination and the flavor of rustic life. These new ideas and reforms laid foundation for later flourishing of poems and prose in Sui-Tang dynasties.

In social development, the handicraft industry was advanced in a wide margin compared to that of the Western Jin owing to the melting and communications of the north and the south.

With the industrious working of the immigrated farmers from the north and the native farmers in the south, enormous wilds were cultivated and empoldered, which made the Yangtze River valley the center of e-conomy following the Yellow River valley in Chinese history.