Demobilization and War of the Eight Princes

When the Jin dynasty was established in 266, Emperor Wu of Jin sought to learn from the mistakes of his predecessor, the Cao Wei, by empowering the princes. Unlike the Wei, the princes were allowed to become military governors and were given personal armies in their fiefdoms. After unifying China in 280, Emperor Wu issued for the demobilization of every province and commandery in the empire and reduced the military authority of the provincial inspector into a civilian role. Only 100 military officials were stationed in large commanderies, while smaller commanderies only had 50.

The emperor had hope that concentrating military power in the hands of the princes would deter the gentry clans from assuming power, but these decisions led to the War of the Eight Princes after his death in 290. His successor, Emperor Hui of Jin, was developmentally disabled, and the princes pitted their armies against each other for control over the empire in light of the new emperor's lack of agency.

While the Jin military weakened itself under the princes, many defenseless commanderies became targets for rebellion by the empire's disgruntled or opportunistic subjects. In the finals years of the Western Jin, tribal subjects collectively known as the Five Barbarians emerged dominant over northern and western China. These Five Barbarians were the Xiongnu, Jie, Qiang, Di and Xianbei.

Southern Xiongnu of Bing province

The migration of the nomadic people into the Chinese interior had been ongoing since the Han dynasty. In 50 CE, a few years after the Xiongnu empire was divided into two, the Southern Xiongnu became vassals to the Han. They moved their court to Xihe Commandery in Bing province and resettled in the frontier commanderies within the Great Wall. They were dependent on trade with the Han and cooperated with them to destroy the rival Northern Xiongnu. Although relations declined in the later years, with the Xiongnu occasionally rebelling, they remained as vassals even after the Han was replaced by the Cao Wei in 220.^[9]

In 216, the warlord, Cao Cao, abolished the chanyu office and divided the Southern Xiongnu into five divisions around Taiyuan Commandery. Gradually throughout the Cao Wei and early Western Jin periods, the Xiongnu elites began expressing resentment towards their new way of life. During the Jiaping era (249–254), the five divisions briefly unified under Liu Bao before the Wei-Jin courts intervened and forced them back into five. Revolts against Jin broke out in 272 and 294 but were both swiftly quelled. As the Xiongnu noble, Liu Xuan, states in the Book of Jin:

“In the past, our ancestors and those of the Han acted like brothers through joy and sorrow. However, since the fall of Han and the rise of Wei and Jin, our titles of chanyus hold no value, and we have not gained a foot of land since. Although we have been bestowed with many noble ranks, our households are all equally low."

Another ethnic group living in Bing at the time were the Jie people. Their exact origins is still debated by scholars today, but it is believed that they were once a part of the Southern Xiongnu and later resided in Shangdang. Between 303 and 304, Bing suffered from a famine which displaced many of the Xiongnu, Jie and other tribal populace. The provincial inspector had these people captured and sold into slavery to fund his army for an ongoing civil war.

Ethnic tensions in Guanzhong

Since establishing their presence in the Hexi Corridor in 121 BC, the Han were in constant conflict with the Qiang people of present-day Gansu and Qinghai. To appease them, the Qiang were sometimes allowed to resettle into the Guanzhong region, as well as the watersheds of the Wei and Jing rivers. There, they lived together with Chinese settlers but faced oppression from the local administrators, which often led to rebellions. Living close to the Qiang were the Di people, who most became tributaries to the Han as the Han expanded westwards.

The fall of Han and the Three Kingdoms period further encouraged the immigration of nomadic people to repopulate devastated areas and provide military power and labour. The Guanzhong region in particular became a contested region between warlords and later between the states of Cao Wei and Shu Han. In 219, Cao Cao relocated around 50,000 Di from Wudu to Tianshui and Fufeng commanderies. The Qiang and Di people were numerous in northwestern China, and they often fought for Wei or Shu depending on their circumstances. Other tribal people who resided in the northwest included the Lushuihu (盧水胡) and Xianbei tribes such as the Tufa (禿髮). The tribes made up around half of the population in Guanzhong.

While Wei kept the situation mostly under control, the northwest descended into chaos under the Western Jin as their governors failed to keep the support of the tribes. In 270, the Xianbei chieftain, Tufa Shujineng, led a multi-ethnic rebellion against Jin in Liang and Qin provinces that lasted until 279, with the rebels briefly taking control over Liang. From 296 to 299, the various tribes rebelled again, this time within Guanzhong and acclaiming the Di chieftain, Qi Wannian as their emperor. These rebellions were accompanied by famines and plagues, with Qi Wannian's rebellion being so severe that it devastated Guanzhong and prompted tens of thousands of refugees to move into Hanzhong and Sichuan in search of food.^[10]

The rebellions, along with the Xiongnu revolts in Bing, raised alarms among a few people in the Jin court. After the unification, the minister Guo Qin (郭欽), advised Emperor Wu to focus on moving the tribal peoples out of the borders. Following Qi Wannian's defeat, another minister, Jiang Tong, submitted an essay titled Xi Rong Lun (徙戎論; Discussion on Relocating the Rong Tribe) to the court, also calling for the tribes' repatriation. However, both proposals were rejected.

Jin and Xianbei alliances

With the decline of the Xianbei confederation, the Murong, Duan and Yuwen tribes migrated to the Liaoxi region. The Murong was the first of the three to associate themselves with the Central Plains dynasties by aiding the Cao Wei in their campaign against Gongsun Yuan. They remained affiliated well after the founding of Jin, and despite a war between both sides from 281 to 289, the Murong resubmitted to Jin and their chieftain, Murong Hui, was appointed Commander of the Xianbei. Meanwhile, in 258, another Xianbei tribe, the Tuoba, occupied the abandon city of Shengle and also became a vassal of Wei and Jin.

At the turn of the 4th century, the Inspector of You province, Wang Jun, sought to consolidate his control over his province amidst the War of the Eight Princes. He allied himself with the neighbouring Duan and a chief of the Yuwen, who provided him with auxiliaries who fought in the campaigns against Sima Ying and Sima Yong. The Xianbei were a deciding factor in Sima Yue's victory in the civil war, but they also partook in the sacking of Ye in 304 and Chang'an in 306, killing thousands of the cities' inhabitants. Their effectiveness encouraged Jin to continue employing them in containing the growing threat of Han-Zhao, with the Tuoba joining on the side of Jin as well.

Climate Change

Modern historians and meteorologists believe that climate change was an important factor in the migration of nomadic peoples into the Chinese interior, as the weather became too cold and dry in the north for agriculture. Chu Coching stated that there was a cold period from the Three Kingdoms to the Northern and Southern dynasties, with relevant historical records reporting cases of extreme weather phenomena, such as the freezings of the Huai River in 226 and the Bohai Sea in 336. Research conducted in the Mu Us Desert also found that desertification took place around the steppe between the Han and Tang dynasties, making it difficult for cities to survive.

There was a severe decline in population; the Han census in 157 was 56.5 million people and 10.7 million household, but Jin census in 280 was only 16 million people and 2.5 million households. The cold and dry weathers prompted Chinese farmers to move to the warmer southlands and steppe peoples to move into northern China for fertile land. During the Taikang era (280–289), the Jin accepted a series of submissions from the Xiongnu living outside the border, with the largest group coming in 286, purportedly at 100,000. Natural disasters and famines became common occurrences and were aggravated by the War of the Eight Princes.^[11][12]

Refugees in Ba-Shu

The people displaced by Qi Wannian's rebellion were from six commanderies in Guanzhong and composed of both Han Chinese and tribal peoples. They initially moved southwards to Hanzhong, where one Di chieftain, Yang Maosou, brought his followers to Chouchi and declared semi-autonomy from Jin in 296. Later, the court allowed the refugees to go further south into the Ba-Shu region. They were scattered throughout Yi and Liáng provinces, where they became hired labourers for the local populace.

Among the refugees was one of their leaders, Li Te. He and his family were Ba-Di people, an ethnic group whose ancestors were Cong people from Ba who moved north and mingled with the Di. In 300, Li Te and his brothers joined the Inspector of Yi in his rebellion against Jin, but later betrayed and ousted him from the provincial capital, Chengdu, sacking it in the process. Li Te soon submitted back to Jin due to the arrival of the army led by the new inspector, Luo Shang but retained a significant amount of influence in the region as an acting representative for the refugee families.

Li Te's Rebellion

In 301, the court in Luoyang ordered the refugees to return to Guanzhong, but they were reluctant to comply as they believed that it was still unstable and they did not have enough supplies to guarantee a safe journey. Li Te extended their stay by negotiating with Luo Shang, but the latter soon became frustrated with the delay and tried to force a move. As conflict appeared inevitable, many of the refugees flocked to Li Te to defend themselves. In winter 301, Luo Shang sent his troops to attack them, beginning a three-year-long rebellion led by Li Te and his family.

Li Te had much success against the Jin forces as he defeated them in several battles. In 303, his forces reached the vicinity of Chengdu where he declared a new reign era, hinting at a new regime. However, before he could realize it, he was abruptly killed in an ambush. Leadership fell to his brother, Li Liu, and after he died at the end of the year, it fell to Li Te's son, Li Xiong. In 304, Li Xiong drove Luo Shang out of Chengdu and established the state of Cheng (renamed Han in 338, thus the name Cheng-Han).

Early years of Cheng-Han

Li Xiong initially declared himself King before promoting himself to Emperor in 306. With Taoism being widespread in Ba-Shu and Hanzhong, he appointed the Taoist hermit, Fan Changsheng as Chancellor. Between Cheng's inception and the fall of Western Jin, Cheng took a slow approach to expansion, only acting when there was a neighbouring refugee revolt. Their most significant gain came in 314, when rebels in Hanzhong surrendered the region to Cheng. Its existence was threatened in 309 when Luo Shang launched an offensive to support rebelling Cheng administrators. Despite losing key commanderies early on, Cheng was eventually successful at recovering them and repelling Jin by 311.

The wars with Li Te and Cheng created more refugees, this time from Yi province moving east into Jing province. Jin forces in the south were unable to concentrate their resources on the southwest due to rebellions in Hubei and Hunan. Between 303 and 304, a Man official, Zhang Chang led a revolt that spread across Jing, Jiang, Xu, Yang and Yu provinces consisting of refugees and people evading the draft to fight against Li Te's rebellion. From 311 to 315, Du Tao, a Han Chinese, led a refugee uprising against Jin in Jing and Xiang (湘州; in modern Hunan) provinces. Unlike Li Te's rebellion, the revolts in Hubei and Hunan were put down by Jin in the end.

Founding of Han-Zhao

In 304, the Xiongnu nobility in Bing province conspired to take advantage of the Jin princes' infighting to break away from the empire. Serving under the prince, Sima Ying, was the Xiongnu general, Liu Yuan. Liu Yuan was the grandson of the Southern Xiongnu chanyu, Yufuluo, although some modern Chinese historians believe he was a member of the non-related but influential Tuge tribe (屠各部) instead. He was a sinicized Xiongnu, having spent his youth as a hostage in the Jin capital Luoyang and being educated with Chinese-Confucian literature. After leaving Luoyang, he served a series of offices under Jin overseeing the Xiongnu, becoming popular among the Xiongnu and Han Chinese in Bing and You provinces.

Liu Yuan's granduncle, Liu Xuan, convinced the Xiongnu to elect Liu Yuan as their leader, so they sent an envoy to Ye, where Liu Yuan was stationed, to inform him of the plot. At the time, Sima Ying was on the verge of defeat as Wang Jun and his tribal allies marched onto Ye. After agreeing to join the plot, Liu Yuan received Sima Ying's permission to return to Bing so that he could gather the Xiongnu to help repel Wang Jun. Once Liu Yuan reached Lishi, he was acclaimed as the new Grand Chanyu and rallied around 50,000 soldiers.^[13]

Later in 304, Liu Yuan established the state of Han (renamed Zhao in 319, thus the name Han-Zhao). Despite being a Xiongnu, Liu Yuan depicted his state as a continuation of the Han dynasty, citing that his ancestor, Modu Chanyu, was married to a Han princess through Heqin. He initially took the imperial title of King, only becoming Emperor in 308 to imitate the ascension of Emperor Gaozu of Han. He also honored the emperors of the Western, Eastern and Shu Han. To bolster his forces, he was willing to accept the Han Chinese and non-Xiongnu tribes to serve under him.^{[14][15][16][17][18][19][20][21][22]}

Rebellions in Hebei, Henan and Shandong

In the next few years, more rebellions began to break out in northeastern China. In 305, the general, Gongshi Fan rebelled in Hebei and in 306, the prefect, Liu Bogen (劉柏根), rebelled in Shandong. The two rebellions were swiftly dealt with by late-306, but Jin was unable to completely wipe out their forces, allowing their remnants to develop into more serious threats. Many of these rebel leaders were Han Chinese, but the most influential of them would prove to be Shi Le, a Jie chief who was previously sold into slavery during the famine in Bing province of 303 and 304.

After Gongshi Fan's defeat, his subordinates, Ji Sang and Shi Le, fled to the pastures of Shandong where they gathered followers, many of who were horse shepherds, and raided the surrounding counties. Their forces grew to such a size that in 307, they sacked the city of Ye and left it to burn for ten days. Around 10,000 people were killed including the city's commander. However, after they left to invade Yan province, they suffered a string of defeats. Ji Sang was killed, but Shi Le survived and made his way to Han.

Liu Bogen's subordinate, Wang Mi, also survived his superior's defeat and fled to Shandong, where he formed a bandit group. His forces grew immensely, and in 307, he invaded Qing and Xu provinces, ravaging the commanderies and killing many of the local officials. Wang Mi then attached himself to Han, and in 308, his rebellion spilled over to Yan and Yu provinces while his forces swelled to the tens of thousands. He was even able to enter Xuchang and empty the city's arsenal before laying siege on Luoyang. However, the siege ended in failure as he was unable to break through the capital's defense. With his momentum coming to a halt, Wang Mi brought his forces over to Han.

Under Liu Yuan, Shi Le and Wang Mi were elevated to powerful commanders. Wang Mi was a friend of Liu Yuan and was thus immediately entrusted with important military affairs. Meanwhile, Shi Le, around the time of joining Han, helped convinced several tribes around Shanxi into joining the state. For his deeds, he was given full command over the armies east of the Taihang Mountains. Although these measures helped Han bolster their forces, it also meant that generals like Shi Le and Wang Mi were effectively warlords, and the Han court have very little power to restrict them.^[23]

Disaster of Yongjia

The War of the Eight Princes had concluded by the start of 307, but Jin’s new paramount authority, Sima Yue, inherited a difficult situation. The civil wars had exhausted the Jin military in the north and left major cities, including Luoyang, vulnerable. Despite quelling them, Ji Sang and Wang Mi’s rebellions saw rebels occupying Ye and Xuchang. Internally, Yue was also desperate to secure his paramountcy and avoid the same fate as his predecessors, especially with the ascension of the abled Emperor Huai of Jin in early 307. Yue was wary of the new emperor and left Luoyang with the imperial army shortly after his enthronement. During his return in 309, he had Emperor Huai’s advisors killed and replaced the veteran palace guards (who participated in various coups) with soldiers from his own fief. While consolidating his power, these acts deepened the enmity between Yue and the emperor.

In addition to constant warfare, the famine in northern China also worsened due to natural disasters. In 309, a great drought was reported to have sunk the Yellow, Yangzi and Han rivers to the point that one could wade their way across them. The following year, locust swarms affected six northern provinces, including the capital region. The war and famines resulted in refugee groups like the Qihuo (乞活; "Begging Life") emerging, either to flee south or to defend themselves against the chaos. Some of them huddled in fortresses, with their leaders becoming known as wuzhus (塢主; "fortress masters"). The Book of Jin described the famine as followed:^[12]

By the Yongjia period [307–12] trouble and disturbances were widespread. From Yongzhou eastward many suffered from hunger and poverty. People were sold [as slaves]. Vagrants became countless…there was a bad plague of locusts…Virulent disease accompanied the famine. The people were murdered by bandits. The rivers were filled with floating corpses; bleached bones covered the fields…There was much cannibalism. Famine and pestilence came hand in hand.

While Shi Le and Wang Mi's forces raided the North China Plain, Liu Yuan's son Liu Cong attacked Luoyang twice in 309 and 310, without success. However, these attacks and the ongoing famine made it apparent to Sima Yue that Luoyang was too exposed to the enemy. In 310, he left the capital with the 40,000-strong imperial army troops to Xiang County (項縣; in present-day Shenqiu County, Henan) to campaign against Shi Le, leaving behind Emperor Huai despite opposition from him. Yue also feared his own generals, particularly Gou Xi, who he had antagonized by taking away his control over Yan province. For this reason, even with the imperial army, Yue was reluctant to go north and campaign in Han's domain, fearing that Gou Xi and the others might cut off his rear.^[13]

After Liu Yuan died in late 310, his successor, Liu He was overthrown by Liu Cong just a week into his reign. After taking the throne, Liu Cong made another attempt to capture Luoyang. Tension between Sima Yue and Emperor Huai reached its breaking point in 311 when Yue discovered the emperor's conspiracy with Gou Xi to depose him. Yue wanted to campaign against Gou Xi, but was so overwhelmed with stress that he grew ill and soon died. Following Yue's death, his followers were unsure on how to proceed, so the imperial army, led by Wang Yan, decided to hold Yue's funeral at his fief in Donghai first. However, Shi Le pursued and defeated the funeral procession at the Battle of Ningping, where reportedly more than 100,000 soldiers perished including Wang Yan himself.^[24]

The defeat of Wang Yan's forces finally exhausted the military capacity of the Jin, leaving Luoyang open to capture. Upon entering the city in 311, the Han armies led by Wang Mi, Huyan Yan and Liu Yao 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; the emperor himself was captured, while his crown prince and clansmen who were in the capital at the time were killed. Gou Xi was also defeated and captured by Shi Le at Mengcheng County. Just a few months later, Han forces led by Liu Can captured Chang'an, briefly placing the two ancient capitals under Han control.^[24]

Restoration in Chang'an

Despite the loss of the emperor and the capital, the Western Jin would survive for another five more years. In 312, a group of Jin generals managed to recapture Chang’an, where they then acclaimed the 12-year-old Emperor Min of Jin (Emperor Huai's nephew) as the new emperor in 313. Elsewhere, Jin governors also refused to surrender and continued to resist Han. Although Luoyang was at hand, the Han court opted to remain in Pingyang, as the former Jin capital was still surrounded by enemies and had been razed by Liu Yao.

Being only a minor upon his ascension, Emperor Min was mostly a figurehead for his closest generals, only retaining his ability to legitimately hand out appointments throughout the empire. Not long after recapturing Chang'an, these generals fought each other in a brief but bloody power struggle, with Emperor Min eventually falling into the hands of the pair, Suo Chen and Qu Yun. Even then, the two men's authority was restricted to Chang'an and its surroundings, as they did not have the capacity to exert their rule over the rest of Guanzhong, let alone outside of it. The Jin administrators in Guanzhong were unenthused about supporting the new government and often hesitant to send out their forces to aid it. Emperor Min had to rely on the Inspector of Qin province, Sima Bao and the Inspector of Liang province, Zhang Gui (later his son, Zhang Shi) in the west to provide him with reinforcements.

Along with the administrators in Guanzhong, the Qiang, Di and other tribes were also left to their own devices and asserted their power over the region. While some of the tribes welcomed and sided with the Han regime, there were also those who remained loyal to Jin and helped in the restoration. Others remained neutral during the conflict and formed independent domains, only submitting to Han-Zhao after the fall of the Western Jin. The two most notable examples were the Di, Pu Hong, in Lüeyang commandery and the Qiang, Yao Yizhong, in Fufeng commandery.

Shi Le's conquest

Since joining Han, Shi Le was active in the northeast and enjoyed a strong degree of control over his own forces. His influence was amplified when, after the Disaster of Yongjia, he assassinated Wang Mi at a banquet and absorbed his army. Liu Cong was powerless to punish him and could only appease him to prevent escalation. Shi Le was virtually in control of Han's eastern domain, with his only challenge coming from Cao Ni in Shandong, who even then was a warlord who waivered his allegiance constantly. Early in the upheaval, Shi Le’s army operated as a roving band that attacked and pillaged counties but never capturing them. After a disastrous campaign to attack Jiankang in 312, he took the advice of his advisor, Zhang Bin, to establish and cultivate a base in Xiangguo (襄國, in modern Xingtai, Hebei).

The strongest Jin forces in the northeast were the Inspector of You province, Wang Jun and the Inspector of Bing province, Liu Kun, who were backed by the Xianbei Duan and Tuoba tribes respectively. The Duan continued their alliance with Wang Jun after the War of the Eight Princes and played a crucial role in hindering Shi Le's forces. In addition to the Duan, Wang Jun was also supported by the Wuhuan tribes. The Tuoba first assisted Jin against Han forces in 305, but their involvement intensified during the reign of Tuoba Yilu, who made a formal alliance with Liu Kun in 309. For their efforts, the Duan received Liaoxi while the Tuoba received Dai Commandery as their fiefs.

However, both Wang Jun and Liu Kun were heavily reliant on their tribal allies.The two governors had trouble maintaining population in their territories, as initially, they would attract thousands of refugees, but just as many people would leave them to join the safer and better-managed Xianbei fiefdoms. Thus, their populations declined as the war and famines began to take their tolls. When Liu Kun lost his capital to Han in 312, he was forced to flee to the Tuoba, who helped him reclaim the city. Wang Jun and Liu Kun were also distrustful of and refused to collaborate with each other, stemming from Liu Kun's role in persuading the court to award Dai Commandery, a commandery under Wang Jun, to the Tuoba.

In the end, Shi Le was able to exploit Wang Jun and Liu Kun's weaknesses. During a siege on Xiangguo in 312, Shi Le's forces captured a cousin of the Duan chieftain, opening up negotiations between the two sides. Convinced by Shi Le's sincerity, the Duan agreed to severe their ties with Wang Jun, and as Shi Le capitalized on his victory, the Wuhuan also defected to Han. Deprived of his tribal forces, Shi Le captured Wang Jun at the latter's own capital in Jicheng and executed him in 314. In 316, the Tuoba fell into civil war and left Liu Kun without his key ally to fend off Shi Le. Soon afterwards, Liu Kun suffered a decisive defeat to Shi Le, prompting his subordinates to surrender the province to Han.

Fall of Chang'an

Liu Yao, having lost Chang'an under his watch, was entrusted by Liu Cong to recapture the city. Shortly after Emperor Min ascended the throne in 313, Liu Yao and the other Han generals immediately began efforts to defeat him. Emperor Min's generals were able to inflict the Han forces some defeats but ultimately failed at halting their advances. In autumn 316, Liu Yao finally laid siege on Chang'an. Suo Chen and Qu Yun mounted a last-ditch defence, but by winter, the food supply within the city had exhausted. Most of the city's inhabitants had either fled or perished, and with no signs of reinforcements, Emperor Min surrendered to Han on 11 December 316.

Sixteen Kingdoms

While Han enjoyed military success, it was also internally unstable. As his reign progressed, Liu Cong began to indulge himself in women and neglected political affairs. The Han court fell into factionalism with Liu Cong's retainers, led by his fathers-in-law and eunuchs, against the rest of the court, during which he had many of his key ministers executed. Meanwhile, Shi Le continued to expand his influence in the northeast through his military exploits as the court failed to keep him in check.

After Liu Cong died in 318, his successor Liu Can and their family were exterminated in a coup by one of his retainers, Jin Zhun. Liu Yao and Shi Le joined forces to defeat Jin Zhun, during which Liu Yao was acclaimed as the new emperor. He relocated the capital to Chang'an and renamed the state to (Former) Zhao in 319, but that same year, Shi Le broke away and founded the Later Zhao, starting a decade-long confrontation that would end in the Han-Zhao's demise.

The founding of Han-Zhao and Cheng-Han in 304 is often seen as the beginning of the Sixteen Kingdoms period, and the Later Zhao is also considered as one of the sixteen. As Jin lost ground in the north, the Zhang clan in Liang province and the Murong tribe in Liaodong became effectively independent. Their natural defenses and stable governance made them popular areas for refugees, with the Murong notably employing Han Chinese officials into their administration. The Zhang clan's regime is known as the Former Liang, but for most of its existence, they remained as a vassal of Jin. The Murong founded the Former Yan in 338 though would only declare independence from Jin in 352. As the period progressed, more of the Sixteen Kingdoms would emerge.

Other regimes that sprang up from the upheaval but are not considered as part of the Sixteen Kingdoms were the Di-led Chouchi, the Tuoba-led Dai, the Duan and Yuwen states in Liaoxi, and the Tiefu-Xiongnu tribe around the Ordos Plateau.

Eastern Jin dynasty

Liu Cong had Emperor Huai and Emperor Min killed in 313 and 318 respectively. Both emperors suffered similar fates; they were forced to serve as Liu Cong's servants before being executed. Following Emperor Min's death, Sima Bao made a claim to the throne but died before he could realize it, and his forces were subsequently crushed by Liu Yao in 320. In Hebei, there were still pockets of Jin resistance after Wang Jun and Liu Kun's defeats, the strongest being a branch of the Duan that remained loyal to Jin in Jicheng, but by 321, they were all defeated by the Later Zhao. The Later Zhao also conquered Shandong from Cao Ni in 323.

After the Eastern Wu fell in 280, the gentry clans in Jiangnan went into a decline as imperial authority was shifted back to Luoyang. In 305, they attempted to breakaway by backing the rebel general, Chen Min in his takeover of the region. However, dissatisfied by his rule, they later revolted and killed him, quickly resubmitting to Jin in 307. Following Chen Min's defeat, Sima Yue stationed the Prince of Langya, Sima Rui at Jianye (later Jiankang) to govern the region, and with the help of the cousins, Wang Dun and Wang Dao, Rui was able to win the support of the gentry clans.

As the upheaval unfolded, Jiankang emerged as a centre of authority in southern China. Safe from the chaos in the north, many northern officials flocked to serve under Sima Rui, and after Emperor Min's capture, the gentry clans backed him to take the throne. The Jiankang regime was uninterested in helping Emperor Min reclaim northern China, or were genuinely too threatened by the refugee uprisings in Hubei and Hunan to avert their resources. When the general, Zu Ti volunteered to lead a northern expedition, Rui permitted it but provided him with very meager supplies and no weapons, armors or soldiers. With Emperor Min's death in 318, Sima Rui declared himself emperor and found the Eastern Jin dynasty, formally shifting the Jin court to the south.

Han Chinese migrations

The chaos and devastation of the north led to a mass migration of Han Chinese to the areas south of the Huai River, where conditions were relatively stable. The southward migration of the Jin nobility is referred to in Chinese as yī guān nán dù (衣冠南渡, lit. "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.

The "Eight Great Surnames" were eight noble families who migrated from northern China to Fujian in southern China due to the uprising of the five barbarians when the Eastern Jin was founded, the Hu, He, Qiu, Dan, Zheng, Huang, Chen and Lin surnames.^{[29][30][31][32][33][34][35]}

The different waves of migration such as the fourth century and Tang dynasty northern Han Chinese migrants to the south are claimed as the origin of various Chen families in Fuzhou, Fujian.^[36] Mass migrations led to southern China's population growth, economic, agricultural and cultural development as it stayed peaceful unlike the north.^{[37][38][39][40][41][42][43]} Yellow registers were used to record the original southern Han Chinese population before the migration and white registers were used to record the massive influx of commoner and aristocratic northern Han Chinese migrants by the Eastern Jin dynasty government.^[44]

After the establishment of the Northern Wei in northern China and a return to stability, a small reverse migration of southern defectors to northern China took place. In Luoyang a Wu quarter was set up for southerners moving north.^{[45][46][47][48][49]} Han Chinese male nobles and royals of the southern dynasties who fled north to defect married over half of Northern Wei Xianbei Tuoba princesses.^[50] Southern Chinese from the southern capital of Jiankang (Nanjing) were deported to the northern capital of Chang'an by the Sui dynasty after reuniting China.^[51]

Han Chinese refugees from the five barbarian uprising also migrated into the Korean peninsula^[52] and into the Murong Former Yan state.^{[53][54][55][56]} Eastern Jin maintained nominal suzerainty over the Murong state until 353 as the Murong accepted titles from them.^[57] An official in the Murong state, Dong Shou defected to Goguryeo.^{[58][59][60][61][62][63]} Han Chinese refugees migrated west into Han Chinese controlled Former Liang.^[64][65][66]

The descendants of northern Han Chinese aristocrats who fled the five barbarians uprising to move south with the Eastern Jin and the local southern Han Chinese aristocrats already in southern China combined to form the Chinese Southern aristocracy in the Tang dynasty, in competition with the northeastern aristocracy and the mixed Han-Xianbei northwestern aristocracy of the former Northern Zhou who founded the Sui dynasty and Tang dynasty.^[67][68] The southern aristocracy only intermarried with each other and viewed themselves as preserving Han culture.^[69][70]

Southern Chinese Daoism developed as a result of a merger of the religious beliefs of the local southern Han Chinese aristocrats and northern Han Chinese emigres fleeing the five barbarians.^[71] The Han aristocrats of both south and north were highly insular and closed against outsiders and descended from the same families who originally hailed from northern China.^[72][73]