Sixteen States (304 to 439 AD) were a collection of numerous short-lived sovereign states in northern China after the retreat of the Jin Dynasty (265-420) to South China and before the establishment of the Northern Dynasties. There were sixteen states established by five barbarian peoples Di, Jie, Qiang, Xianbei and Xiongnu in northern China coexisting or successively, namely, Han Zhao, Later Zhao, Cheng Han, Former Liang, Later Liang, Northern Liang, Western Liáng, Southern Liang, Former Yan, Later Yan, Northern Yan, Southern Yan, Former Qin, Later Qin and Western Qin and Xia. Thus Sixteen States were also called Sixteen States of Five Barbarian Peoples.
The weakness of central government allowed many minority tribes to intrude on Chinese territory in the northwest. With the sixteen year long crisis of the Jin court during the Rebellions of the Eight Princes, military leaders of Chinese settlers and minority tribes saw their chance to become independent from the Jin Dynasty.
The period of the Sixteen States can be divided into three stages. From 300 to 350, the Former Liang, the two Zhao and the Cheng Han States ruled the north and Sichuan. The dominating force from 350 to 380 is the Former Qin State. After 380, northern China was divided up into many short-lived and ever-changing states that are eventually destroyed by the Northern Wei around 430.
The Sixteen States of the Five Barbarian Peoples are not enlisted among the acknowledged dynasties. Although their rulers adopted Chinese customs and the Chinese administration system to govern their realms, they are not seen as righteous rulers of China. Most of the short-lived states were not able to develop a real working government. Their politics were all short-term and in many cases were determined by a simple surviving strategy.
More than a hundred years of diverse minority states on Chinese proper soil meant the population suffered during that period. The tenant farmers had not only to endure the permanent war campaigns, together with natural disasters and calamities, but also had to deliver tax and corvée labour for their landowners and the alien rulers. A typical measure to support the economical and fiscal needs of the government was to resettle peasants around the capital. This short-eyed policy of the "barbarian" rulers led to the economical and cultural backwardness of China's north during the 4th and 5th centuries.
The period of Sixteen States witnessed the frequent communication both between Han people and minorities, as well as among different minorities. As a result, the ethnic constituents of the northern Chinese population changed, with the former "barbarians" gradually mixing with the Han Chinese population.