Wu Hu uprising

The Wu Hu Uprising (, literally 'the throwing of China into disorder by the five barbarian tribes') refers to a series of uprisings, occurring between 304 and 316, carried out by five non-Chinese tribes or tribal confederacies against the Western Jin Dynasty. The five tribes, namely the Xiongnu, Xianbei, Jie, Qiang and Di, successfully captured the Western Jin capital of Luoyang as well as Emperor Huai of Jin, destroying the Western Jin regime, after which a large series of regional states and regimes were set up, the most prominent of which are known as the Sixteen Kingdoms (五胡十六國, 'sixteen kingdoms of the five barbarians').

Background
The southward migration of nomadic tribes into the lands around the Yellow River had been ongoing since the Eastern Han Dynasty, due to several reasons. Military and diplomatic successes provided an incentive for nomads to move into closer contact with China, while the wars of the later Three Kingdoms period led also to an incentive to encourage this immigration, in order to repopulate previously devastated areas and provide military power and labour.

By the end of the 4th century, the nomadic tribes had moved into the Guanzhong area as well as the watersheds of the Wei and Xing rivers, practically surrounding the Jin capital in Luoyang. At the same time, the accession of Emperor Hui of Jin, who was possibly developmentally disabled, led to a struggle between the princes of the ruling Sima family to control him, sparking off the War of the Eight Princes.

Beginnings of the uprising
The War of the Eight Princes lasted for more than a decade, severely weakening the economy and military capacity of the Western Jin. At the same time, the nomads were also being enlisted by the princes as military forces; one such force of Xianbei, under the command of Sima Yue, captured Chang'an in 306.

Taking advantage of this period of weakness, the different non-Chinese peoples began to openly occupy territory and proclaim new regimes. The Di chief Li Xiong captured Chengdu in 304, proclaiming the kingdom of Cheng Han. The most serious initial revolt, however, was Xiongnu chieftain Liu Yuan, who proclaimed the kingdom of Han Zhao in 304 as well, in the northern heartland of the Jin dynasty.

Jin defeat and Disaster of Yongjia
The Jin Dynasty was ineffective in its attempts to halt the uprising. The Jin capital, Luoyang was open to Liu Yuan's son Liu Cong (who was now commander of the Wu Hu forces), and he attacked Luoyang in 309 and 310 CE twice, without success. However, the Jin Chancellor Sima Yue fled Luoyang in 310CE with 40,000 troops to Xiangcheng in Henan in an attempt to flee this threat.

After Sima Yue's death, the main Jin forces in Henan, led by Wang Yan, decided to proceed to Shantung to defeat Shi Le, a general of Jie ethnicity under Liu Cong. but was defeated by the Wu Hu forces and more than 100,000 soldiers perished, including Wang Yan himself.

The defeat of Wang Yan's forces finally exhausted the military capacity of the Jin, leaving the capital open to capture. Upon entering the city, the Wu Hu engaged in a massacre, razing the city and causing more than 30,000 deaths. This event in Chinese history was known as the Disaster of Yongjia, after the era name of Emperor Huai of Jin; the emperor himself was captured, while his crown prince and clansmen were killed.

Although the main Jin regime in the North was defeated, Jin forces continued to hold three provinces in the North, namely Youzhou, Liangzhou, and Bingzhou. These provinces, however, were cut off from the remnant Jin forces now in the South and eventually overrun, reducing Jin control to the area south of the Huai river.

Aftermath
The overrunning of the Western Jin had long-lasting effects on both the north and south of China. In the conquered areas, the different non-Chinese leaderships quickly established a large series of kingdoms and states, most of which were short lived; this era of fragmentation and state creation lasted for more than a century, until the Northern Wei regime finally unified northern China in 439 and became the first of the Northern Dynasties.

The chaos and devastation of the north also led to a mass migration of Han Chinese to the areas south of the Huai River, where conditions were relatively stable. This exodus is known historically as the Southbound migration of the Jin nobility (Chinese: 衣冠南渡, literally 'garments and headdresses moving south'). Many of those who fled south were of prominent families, who had the means to escape; among these prominent northern families were the Xie clan and the Wang clan, whose prominent members included Xie An and Wang Dao. Wang Dao, in particular, was instrumental in supporting Sima Rui to proclaim the Eastern Jin Dynasty at Jiankang and serving as his chancellor. The Eastern Jin, dependent on established southern nobility as well as exiled northern nobility for its survival, became a relatively weak dynasty dominated by regional nobles who served as governors; nonetheless it would survive for another century as a southern regime.

While the era was one of military catastrophe, it was also one of deep cultural interaction. The nomadic tribes introduced new methods of government, while also encouraging introduced faiths such as Buddhism. Meanwhile, the southward exodus of the cultured Jin elite, who then spread across the southern provinces including modern-day Fujian and Guangdong, further integrated the areas south of the Yangtze River into the Chinese cultural sphere.