When the last Han emperor abdicated in 220, each of the warlords proclaimed himself ruler, beginning what is known as the Three Kingdoms Period (220-265). The northern state, Wei, was the strongest, but before it had succeeded in unifying the realm, Sima Yan, a Wei general, led a successful coup in 265 and founded the Jin dynasty. By 280 he had reunited the north and south, but unity was only temporary, as the Jin princes began fighting among themselves.

  The non-Chinese groups of the north seized the opportunity to attack, and by 317 the Jin had lost all control of North China. For the next 250 years, North China was fractured and ruled by numerous non-Chinese dynasties, while the south was ruled by a sequence of four short-lived Chinese dynasties, all centered at present-day Nanjing.
  The southern rulers had to contend with a powerful, hereditary aristocracy that had become entrenched in government posts. The Wei had granted public offices based on the nine rank system, which was originally determined by assessments of character and talent. However, in the south the system had degenerated to the point where the standing of the candidate�s family determined his post. The aristocratic families judged themselves and others by the status of their ancestors, would marry only with families of equivalent pedigree, and compiled lists and genealogies of the most eminent families. By securing nearly automatic access to higher government posts through the nine rank system, the aristocrats were assured of government salaries and exemptions from taxes and labor service. These families saw themselves as maintaining the high culture of the Han, and many excelled in poetry writing and witty conversation. At the same time, many also were able to amass large estates, which were worked by poor refugees from the north. At court, the aristocrats often looked on the emperors of the successive dynasties as military men rather than men of culture.
  Despite the political instability of the successive dynasties, the southern economy prospered. To pay for an army and support the imperial court and aristocracy in high style, the government had to expand the area of taxable agricultural land, which it accomplished by both settling migrants on the land and improving tax collection. The potential of the south for agriculture was greater than that of the north because of its temperate climate and ample water supply.
  In the north, none of the states established by non-Chinese lasted very long until the Xianbei tribe founded the Northern Wei dynasty (386-534). By 420 the Xianbei had secured control. During the second half of the 5th century, the Xianbei adopted a series of policies designed to strengthen the state. To promote agricultural production, they adopted a system to distribute land to peasants. The capital was moved from its site near the northern border to Luoyang, the old capital of the Eastern Han and Jin. The population within the Northern Wei realm contained considerably more Chinese than Xianbei. Recognizing this, the Xianbei rulers employed Chinese officials, adopted Chinese-style clothing and customs at court, and made Chinese the official language. Xianbei tribesmen, however, still formed the main military force. They resented the growth of Chinese influence and rebelled in 524, sparking a decade of constant warfare. For the next 50 years, North China was torn apart by struggles between different contenders for power.

  The Spread of Buddhism During this period of near-constant political and military strife, Buddhism found a receptive audience in China, while the influence of Confucianism waned. Buddhism had arrived in China in the 1st century AD as the religion of merchants from Central Asia. During the next three centuries, the Chinese encountered a great variety of ideas and practices identified as Buddhist. Buddhism differed markedly from earlier Chinese religions and philosophies. A universal religion, it embraced all people, regardless of their ethnicity or social status. It also had a founding figure, the Indian prince Siddhartha (Buddha), who lived during the 6th and 5th centuries BC. To many Chinese, Buddhism seemed at first a variant of Daoism, as Daoist terms were used to translate Buddhist concepts. A more accurate understanding of Buddhism became possible after Kumarajiva (343?-413?), a Buddhist monk from Central Asia, settled in Chang�an and directed several thousand Chinese monks in the translation of Buddhist texts.
  The Buddhist monastic establishment grew rapidly in China. By 477 there were reportedly 6,478 Buddhist temples and 77,258 monks and nuns in the north. The south was said to have 2,846 temples and 82,700 clerics some decades later. Given the traditional importance of family lines in China, it was a major step for a man to become a monk. He had to give up his surname and take a vow of celibacy, breaking from the ancestral cult that connected the dead, the living, and the unborn. Buddhists who did not become monks or nuns often made generous contributions to the construction or beautification of temples. Among the most generous patrons were rulers, in both the north and south. Women turned to Buddhism as readily as men. Although being born a woman was considered inferior to being born a man, it was also considered temporary because in the next life a woman could be reborn as a man, and women were encouraged to pursue salvation on terms nearly equal to men.
  China also had critics of Buddhism, who labeled it immoral, unsuited to China, or a threat to the state because monastery land was not taxed. By the end of the 6th century, critics had twice convinced the court to close monasteries and force monks and nuns to return to lay life. These suppressions did not last long, however, and no attempt was made to eliminate private Buddhist belief.