The Jin dynasty was an imperial dynasty of China that existed from 266 to 420. It was founded by Sima Yan (Emperor Wu), eldest son of Sima Zhao, who had previously been declared the King of Jin. The Jin dynasty was preceded by the Three Kingdoms period, and was succeeded by the Sixteen Kingdoms in northern China and the Liu Song dynasty in southern China.

There are two main divisions in the history of the dynasty. The Western Jin (266–316) was established as the successor to Cao Wei after Sima Yan usurped the throne from Cao Huan. The capital of the Western Jin was initially in Luoyang, though it later moved to Chang'an (modern Xi'an, Shaanxi province). In 280, after conquering Eastern Wu, the Western Jin reunited China proper for the first time since the end of the Han dynasty, ending the Three Kingdoms era. However, 11 years later, a series of civil wars known as the War of the Eight Princes erupted in the dynasty, which weakened it considerably. Subsequently, in 304, the dynasty experienced a wave of rebellions and invasions by non-Han ethnicities termed the Five Barbarians, who went on to establish several short-lived dynastic states in northern China. This inaugurated the chaotic and bloody Sixteen Kingdoms era of Chinese history, in which states in the north rose and fell in rapid succession, constantly fighting both one another and the Jin.