China Between the Han and Tang: Division, Migration and Reunification

Between the end of the Han dynasty in 220 and the Sui conquest of the southern Chen dynasty in 589, political authority repeatedly divided and reunified across the regions of the Yellow River and Yangtze River. Courts rose in northern cities such as Luoyang and Chang’an, while successive southern regimes governed from Jiankang, near modern Nanjing. These centuries were not simply a pause between the Han and Tang empires: migration, military competition and new political arrangements changed how people lived and how rulers governed.

Historians use several overlapping labels for this era. The “Six Dynasties” can refer to six successive courts based at Jiankang, while “Three Kingdoms, Two Jin, Northern and Southern dynasties” describes a broader sequence of states. The “Sixteen Kingdoms” is a conventional name for a succession of northern regimes, not a claim that exactly sixteen states existed at once. These terms reflect different ways of organising a complex history, in which northern and southern courts often existed at the same time.

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From the Three Kingdoms to a brief Jin reunification

As Han imperial authority weakened, powerful generals established independent bases. In 220, the last Han emperor gave up the throne, and three rival states took shape: Cao Wei in the north, Shu Han in the southwest and Eastern Wu in the southeast. Cao Wei conquered Shu Han in 263. The Sima family, which had come to dominate Cao Wei’s court, then replaced its ruling house and established the Western Jin dynasty in 266. After conquering Eastern Wu in 280, Jin briefly reunited much of the former Han realm.

The unity proved fragile. Rivalries among members of the ruling Sima family led to the War of the Eight Princes, a civil conflict from 291 to 306 that weakened the court and its armies. Groups with origins in the northern and northwestern borderlands had already been resettled within the empire, including as soldiers and agricultural workers. As the Jin conflict deepened, some of their leaders established states of their own. In 311, a Han-Zhao force captured Luoyang; Chang’an fell in 316. The Western Jin court could no longer hold northern China.

A Jin prince, Sima Rui, established a successor court at Jiankang in the south, becoming emperor in 318. This Eastern Jin regime ruled from 317 to 420, while a changing succession of states competed for power in the north. Some northern kingdoms were founded by leaders from Xiongnu, Jie, Qiang, Di or Xianbei communities; others were led by Han Chinese. The political map changed often, and rulers drew on different military groups and administrative traditions to hold territory.

Migration and the changing balance between north and south

Warfare and political upheaval prompted substantial migration from northern China to the Yangtze basin. Officials, landowning families and other refugees brought court practices, literary traditions and administrative experience with them. Jiankang became a political and cultural centre, but the south was not an empty landscape awaiting settlement. Migrants lived alongside established local communities, and southern rulers had to negotiate authority with local leaders as their reach extended into new areas.

Over time, migration and expanding agriculture helped change the south’s demographic and economic position. Irrigated rice cultivation and the growth of settlements supported a larger population and more substantial regional centres. Estimates suggest that the Yangtze region’s share of China’s population rose markedly during the period, though figures for these centuries are approximate. The south became increasingly important to the resources and political calculations of courts on both sides of the divide.

The north also changed through migration and political integration. Many people of steppe or frontier backgrounds had long-standing connections with the empire, and their identities and political affiliations could shift. Northern rulers recruited Chinese officials and used established forms of imperial government; Han elites, in turn, served courts founded by non-Han ruling families. Intermarriage and shared political life further complicated any simple division between “Chinese” and “non-Chinese.”

Different courts, military power and family influence

In the south, influential families held land and commanded networks of dependents. Their local wealth and status could help them secure official posts and limit the state’s access to workers and tax revenue. During the Eastern Jin, these families had considerable influence at court. Later southern dynasties, including the Liu Song, Southern Qi, Liang and Chen, were founded by military leaders. Their rulers sought to strengthen the central government and draw military authority away from powerful families, but control over the regions remained difficult.

Northern courts faced different pressures. In parts of the north, insecurity encouraged local families to form fortified communities for defence. At the same time, rulers depended on military organisations and alliances that could bring together people of varied backgrounds. Northern governments incorporated literate officials into their administrations, while military families remained important to political authority. These arrangements did not follow a single model: courts adjusted their institutions and public identities to meet changing military and political needs.

Both northern and southern courts supported military and cultural activity. Southern rulers relied on armies and faced recurring conflict; northern courts fostered scholarship, religion and elaborate court culture. Envoys, officials, merchants and migrants carried ideas and practices between regions even when the two sides were rivals.

Northern Wei and the reshaping of northern rule

The Northern Wei, founded by the Tuoba Xianbei, conquered the Northern Liang and brought northern China under one court in 439. Its rulers governed a large population with varied traditions and worked to strengthen their administration. Under Emperor Xiaowen in the late fifth century, the court adopted a programme that encouraged Xianbei elites to use Chinese surnames and court dress, learn the Chinese language and form marriage ties with established Chinese families. The court also moved its capital from Pingcheng to Luoyang and brought northern warriors to the new centre.

The Northern Wei divided in the 530s into eastern and western courts, later replaced by Northern Qi and Northern Zhou. In 577, Northern Zhou conquered Northern Qi and reunited the north. These successive regimes adapted administrative practices while relying on military and aristocratic networks. The northwestern elite formed through these struggles helped supply the ruling groups of Sui and Tang.

Buddhist patronage created durable institutions and monumental settings in these changing states. Northern Wei rulers sponsored the rock-cut caves at Yungang near Pingcheng, filling them with large Buddhist images. Work at Longmen developed near Luoyang after the court’s move. Monasteries, sculpture and translated texts connected religious teaching with patrons, artisans and communities.

Traders and Buddhist missionaries from Central Asia also settled in China, some entering official service while maintaining their own customs and religions. Their presence joined the migration of northern Chinese families to the south in reshaping regional society. Political borders divided courts while people, books and religious ideas continued to cross them.

Sui reunification and the work of governing

Yang Jian, a senior figure at the Northern Zhou court, took power in 581 and founded the Sui dynasty as Emperor Wen. His position reflected the influence of the military and political elite that had developed in the northwest. Sui first consolidated the north and then moved against the Chen dynasty in the south. In 589, Sui forces captured Jiankang and ended Chen rule, bringing the north and south under one imperial court again.

Reunification required more than military victory. The Sui court reorganised central government around offices responsible for drafting and reviewing orders and carrying out administration. Six central ministries handled major areas of government, including appointments, revenue, rites, military affairs, law and public works. This arrangement drew on earlier institutional experiments and became an important model for the Tang government. Locally, the Sui reduced the number of administrative layers, aiming to make it easier for the central court to oversee officials and regions.

The state also sought more direct access to land, labour and taxes. The equal-field system allocated farmland according to rules set by the government, with the aim of supporting cultivation and limiting the independent power of large landholders. Household registration helped the state identify people liable for taxes and labour service, including those who had previously been attached to powerful families. These measures strengthened government revenues and control, but did not erase regional differences or unequal access to resources. The Sui also used examinations to select some officials. This offered a route beyond inherited connections, although the system was still developing and family status continued to matter.

Transport was another instrument of rule. Sui rulers connected and extended waterways, many of them based on existing rivers or older canals, to move grain and other supplies between regions. The expanding canal network linked Luoyang with agricultural areas to the east and south and supported the movement of troops. It helped strengthen the connection between northern political centres and the south’s growing economic resources. Building and maintaining these routes, along with capitals and other public works, demanded large amounts of compulsory labour.

The costs of centralisation and the transition to Tang

Sui reunification imposed heavy demands on households. Under Emperor Yang, construction projects and repeated campaigns against Goguryeo on the Korean Peninsula required taxes, transport and compulsory labour. Rebellions spread in the 610s. Yang was killed in 618, the conventional end of the dynasty, while rival Sui claimants continued into 619. The Tang had already been founded in 618 and still had to defeat competing regional powers.

The Sui’s short rule did not undo the changes of the preceding centuries. Its institutions and transport projects built on developments under northern and southern courts, and many were carried forward by the Tang, founded in 618. Buddhism had also spread widely during the centuries of division, supported by rulers and religious communities in both north and south. Migration and political competition had moved the centre of population and power southward while bringing northern and southern elites into sustained contact. Reunification restored a single court, but it did so across a realm whose regional centres, ruling groups and cultural traditions had been reshaped by centuries of change.

For the wider setting, see Chinese States and Dynasties: How Political Power Changed from Zhou to Qing.