Northern and Southern dynasties
The Northern and Southern dynasties was a period of political division in the history of China that lasted from 420 to 589 AD, following the tumultuous era of the Sixteen Kingdoms and the Eastern Jin dynasty. It is sometimes considered to be the latter part of a longer period known as the Six Dynasties. The period featured civil war and political chaos. However, it was also a time of flourishing arts and culture, advancement in technology, and the spread of Mahayana Buddhism and Taoism. The period saw large-scale migration of Han Chinese people to lands south of the Yangtze. It came to an end with the unification of China proper by Emperor Wen of the Sui dynasty in 589 AD.
During this period, the process of sinicization accelerated among the non-Han ethnicities in the north and the indigenous peoples in the south. This process was also accompanied by the increasing popularity of Buddhism in both northern and southern China. Daoism gained influence as well, with two essential Daoist canons written during this period. Additionally, many notable technological advances occurred during this period. The invention of the stirrup during the earlier Jin dynasty helped spur the development of heavy cavalry and their use in warfare. Historians also note advances in medicine, astronomy, mathematics, and cartography. Intellectuals of the period include the mathematician and astronomer Zu Chongzhi, and astronomer Tao Hongjing.
Background
After the collapse of a unified China proper under the Eastern Han dynasty in 220, China moved into the Three Kingdoms period. Of these, the kingdom of Cao Wei was the strongest, followed by Eastern Wu and Shu Han. Initially, they were in a relatively stable formation. After a 249 coup by Sima Yi, the Sima family essentially controlled Cao Wei and the conquest of Shu Han by Cao Wei followed in late 263.Following a failed coup by the ruling Cao family against the Sima family in June 260, the final Cao ruler abdicated in February 266. Sima Yan then founded the Western Jin dynasty. The conquest of Eastern Wu by Western Jin occurred in 280, ending the Three Kingdoms period and reuniting China proper.
However, the Western Jin reunification was short-lived; the ascension of the developmentally disabled Emperor Hui of Jin gave rise to the War of the Eight Princes, a period when corruption was rampant and the ruling princes pitched their armies against one another for paramountcy over the empire. In the previous centuries, numerous nomadic tribal groups, collectively known in recent historiography as the Five Barbarians, were forcibly resettled in northern and northwestern China, either to serve as frontier auxiliaries or as farmhands. The civil wars of the Jin princes severely weakened the imperial military while famines and uprisings spread throughout the north, allowing the Five Barbarians to exploit the chaos and seize power. In 311, the Han-Zhao dynasty, founded by descendants of the Xiongnu people, sacked Luoyang and captured the Jin emperor in the Disaster of Yongjia. A similar fate met Chang'an in 316, and the last emperor of the Western Jin was soon put to death.
Amidst the calamity, a scion of the imperial house, Sima Rui was stationed south of the Huai River, where the situation was relatively stable and peaceful compared to the north. Many northern officials fled and found refuge in his domain. In 318, after the death of the last emperor, Sima Rui reestablished the dynasty at Jiankang, known in historiography as the Eastern Jin dynasty. As the Eastern Jin cemented their power in the south, the north remained tumultuous and gave way to numerous short-lived dynasties known as the Sixteen Kingdoms. Many of the Sixteen Kingdoms were founded by the Five Barbarians, though some were also established by the Han Chinese.
Very few of the Sixteen Kingdoms came close to unifying the north, and even the Former Qin dynasty that managed to do so in 376 swiftly disintegrated less than a decade after their defeat at the Battle of Feishui in 383. The Eastern Jin launched several expeditions to reclaim their loss territory, but fell short due to internal strife and conflicting interests among the ruling elites. Eventually, the commander, Liu Yu ended the Eastern Jin after he seized the throne from Emperor Gong of Jin and founded the Liu Song dynasty in 420, officially beginning the Northern and Southern dynasties period. The Sixteen Kingdoms era also came to an end in 439, after the Northern Wei dynasty, founded by the Tuoba tribe of Xianbei ethnicity, conquered the rest of the northern states and ruled over a unified northern China for roughly a century.
Northern dynasties
The Northern dynasties began in 439 when the Northern Wei conquered the Northern Liang and united the north. It ended in 589 when the Sui dynasty conquered the Chen dynasty. It can be divided into three time periods — the Northern Wei, the Eastern and Western Weis, and the Northern Qi and Northern Zhou. The Northern, Eastern, and Western Weis as well as the Northern Zhou were established by the Xianbei people, while the Northern Qi was established by a Xianbei-influenced ethnic Han.In the north, local ethnic Han gentry clans responded to the chaos by constructing fortified villages. These clans would then carve de facto fiefs out of these highly cohesive family-based self-defense communities. Lesser peasant families would work for the dominant clan as tenants or serfs. The chaos also allowed these Han gentry families to avoid government service before the Northern Wei court launched the sinicization movement. Northern gentry were therefore highly militarized as compared to their refined southern counterparts, and this distinction persisted well into the Sui and Tang dynasties centuries later.
Northern Wei (386–535)
Rise to power
During the Sixteen Kingdoms period, the Tuoba family of the Xianbei were the rulers of the state of Dai. Although it was conquered by the Former Qin in 376, the Qin's defeat at the Battle of Fei River in 383 resulted in their collapse. Tuoba Gui, the grandson of the last prince of Dai, restored the fortunes of the Tuoba clan, renaming his state Wei with its capital at Shengle in 386. Under the rule of Emperors Daowu, Mingyuan, and Taiwu, the Northern Wei progressively expanded. The establishment of the early Northern Wei state and the economy were also greatly indebted to the father-son pair of Cui Hong and Cui Hao. Initially, Tuoba Gui submitted as a vassal to the stronger Later Yan state, but after relations broke down, the two sides went to war. Despite his disadvantage, Tuoba Gui was able to repel a major Yan attack in 395, and the following year, he launched his own invasion deep into Yan territory. The Yan was split into two and capitulated most of their territory, allowing the Wei to occupy the Central Plains by 398. Following this victory, Tuoba Gui moved his capital to Pingcheng, and in 399, he declared himself emperor, posthumously known as Emperor Daowu.Due to Emperor Daowu's cruelty, he was killed by his son Tuoba Shao, but crown prince Tuoba Si managed to defeat Tuoba Shao and eventually took the throne as Emperor Mingyuan. Though he managed to conquer Liu Song's province of Henan, he died soon afterward. Emperor Mingyuan's son Tuoba Tao took the throne as Emperor Taiwu. Due to Emperor Taiwu's energetic efforts, Northern Wei's strength greatly increased, allowing them to repeatedly attack Liu Song. After dealing with the Rouran threat to his northern flank, he engaged in a war to unite northern China. With the fall of the Northern Liang in 439, Emperor Taiwu united northern China, ending the Sixteen Kingdoms period and beginning the Northern and Southern dynasties period with their southern rivals, the Liu Song.
Even though it was a time of great military strength for the Northern Wei, Rouran harassment from the north forced them to divert their focus from their southern expeditions. After uniting the north, Emperor Taiwu also conquered the powerful Shanshan kingdom and subjugated the other kingdoms in the Western Regions. In 450, Emperor Taiwu once again attacked the Liu Song and reached Guabu, threatening to cross the river to attack Jiankang, the Liu Song capital. Up until this point, the Northern Wei military forces had dominated the Liu Song forces. However, they took heavy casualties. The Northern Wei forces plundered numerous households before returning north.
File:NorthernWeiMaitreya.JPG|thumb|left|upright|Northern Wei Buddha Maitreya gilt-bronze figurine, 443
At this point, followers of the Buddhist Gai Wu rebelled. After pacifying this rebellion, Emperor Taiwu, under the advice of his Daoist prime minister Cui Hao, proscribed Buddhism — the first of the persecutions of Chinese Buddhism known as the Three Disasters of Wu. At this late stage in his life, Emperor Taiwu meted out cruel punishments, which led to his death in 452 at the hands of the eunuch Zong Ai. His death sparked off turmoil that only ended with the ascension of Emperor Wencheng later that same year., an ethnic Qiang court eunuch and the favourite of Empress Dowager Wenming, patronized Buddhism lavishly. He constructed Cave 9–10, the most highly decorated of the Yungang Grottoes, and had a temple constructed in 488 at Lirun, Fengyi, which was his birthplace according to the Booke of Wei. Wang Yu may have been castrated during the suppression of a 446 Qiang rebellion since the Northern Wei would castrate rebel tribes' young elite.
In the first half of the Northern Wei dynasty, the Xianbei steppe tribesmen who dominated northern China kept a policy of strict social distinction between them and their Han subjects. Ethnic Han were drafted into the bureaucracy, employed as officials for jobs such as collecting taxes. However, the Han were kept out of many higher positions of power. They also represented the minority of the populace where centers of power were located.