Feudal society developed through a period of disunity in China in the Three Kingdoms, Western Jin and Eastern Jin, the Southern and Northern Dynasties, and the short-lived Sui Dynasty to the reunification of the country in the 289-year-old Tang Dynasty, one of the most glorious eras in Chinese history. The Three Kingdoms period, in which the rival states of Wei, Shu and Wu existed side by side, dates approximately from 220 to 280 (or as far back as 196 if calculated from the time that the Wei rose as a political entity). The Western Jin, ruled by four emperors of three generations, lasted 52 years, from 265 to 317; the Eastern Jin, ruled by 11 emperors of four generations, extended over 103 years, from 317 to 420. The Southern and Northern Dynasties period, 420-589, covers 169 years, starting from the two rival dynasties of Song and Northern Wei and ending with the conquest of the Chen by the Sui, and going through the intertwining period of the Qi and the Liang in the south and the Eastern Wei, the Western Wei, the Northern Qi and the Northern Zhou in the north. The dynasty of Sui, 581-618, had just two emperors of two generations on the throne for only 37 years. The 289-year-old Tang Dynasty, 618-907, was ruled by 20 emperors and 1 empress belonging to 14 generations. The Western and Eastern Jin dynasties also saw a number of independent local regimes, known in Chinese history as the Sixteen States.
The defeat of the Yellow Turban Uprising at the end of the Eastern Han Dynasty was followed by a tangled warfare of more than ten years between the various local feudal lords which was to end with the country divided and ruled by three of them. Cao Cao, who had been building up his political and military strength in the middle and lower Yellow River valley, forced Emperor Xian to move his capital to Xuchang (in present-day Henan Province) in 196 and, in the emperor's name, continued to expand his influence. However, Cao Cao found a formidable obstacle in Yuan Shao who had grown strong in Jizhou and Youzhou, both in present-day Hebei Province. Cao Cao and Yuan Shao fought a decisive battle in 200 at Guandu (now Zhongmou County, Henan Province), where Cao Cao's smaller forces bested those of Yuan Shao. In the two or three years that followed, Cao Cao cleared off Yuan Shao's remaining forces and brought the entire middle and lower Yellow River valley under his control.
Around the time of the Battle of Guandu, the southern-based Sun Quan, who had carried on the cause pioneered by his father and elder brother, was ruling in the lower Yangtze River valley. Liu Bei, who claimed to be connected with the Han royal house, was also preparing for a bid for power. He had in his brain-trust the great statesman and military strategist Zhuge Liang and the services of the renowned generals Guan Yu, Zhang Fei and Zhao Yun. However, without a stable political base, Liu Bei had to bide his time by seeking the patronage of Liu Biao, the Prefect of Jingzhou (the greater parts of modern Hubei and Hunan provinces and southwestern Henan Province).
In 208, Cao Cao led a massive force southward to capture Jingzhou, chase Liu Bei around, and pose a direct menace to Sun Quan. At Zhuge Liang's instance, Liu Bei and Sun Quan decided to put up joint resistance to Cao Cao. Sun Quan's army, led by its field marshal Zhou Yu, set fire to scores of Cao Cao's war vessels on the Yangtze River at Chibi (Note: The site is identified as Chijishan to the west of present-day Wuchang County, Hubei, or Chibishan to the northwest of Puqi County, also in Hubei.). Taking advantage of the ensuing confusion, the allied forces of Sun Quan and Liu Bei, totaling less than 50,000, launched an all-out attack and crushed the hostile army that boasted more than 200,000 men. After Cao Cao pulled back to his northern base, Sun Quan consolidated his position in the south while Liu Bei seized part of the regions under the jurisdiction of Jingzhou Prefecture and later took Yizhou (mostly in present-day Sichuan Province) in the west. And so a situation arose in which the country was divided and ruled by the three feudal lords.
After Cao Cao's death in 220, his son, Cao Pi, deposed the Eastern Han Emperor Xian and proclaimed himself Emperor of Wei, with Luoyang as his capital. The following year, Liu Bei declared himself Emperor of Han, historically known as the Kingdom of Shu or Shuhan, and made Chengdu his capital. In 229, following the examples of Cao Pi and Liu Bei, Sun Quan called himself Emperor of Wu with the capital at Jianye (now Nanjing City, Jiangsu Province). These kingdoms—Wei, Shu and Wu—are known as the Three Kingdoms in Chinese history.
Before the Battle of Guandu, Cao Cao had introduced a land reclamation system (Note: A system whereby destitute peasants placed under military officers were organized into civilian colonies to work the land while soldiers, when not fighting, were encouraged to grow crops in military colonies.) in the Xuchang area with excellent results. After setting up the Kingdom of Wei, Cao Pi enforced the system on a larger scale, had large numbers of water conservancy works built and many paddy fields opened up, quickly reviving and developing the war-torn economy in the Yellow River valley. Politically, the Wei had many more talented people in its service than the two other states because Cao Cao promoted people to important posts on their merit rather than on their family background.
In the Kingdom of Wu the land reclamation system was also introduced extensively in the Yangtze and Huaihe river valleys. Irrigation works were built in what is now Zhejiang Province and advanced production technique was brought from the north to develop the lower Yangtze River areas. The Kingdom of Wu was also enthusiastic about forging ties with the outside world. Under orders from Sun Quan in 230, Wei Wen and Zhuge Zhi led a large fleet with 10,000 soldiers aboard to Yizhou (now Taiwan). Three years later, another Wu fleet of the same size called at Liaodong along the northeastern coast and brought back some of the local fine-breed horses. Sun Quan also sent Kang Tai and Zhu Ying as his envoys to various states on the South China Sea. Upon their return, Kang Tai and Zhu Ying wrote books on their travels. Merchants from the Roman Empire came by the South China Sea route to trade in Wu, some of them staying as long as seven or eight years.
As Prime Minister of the Kingdom of Shu, Zhuge Liang worked hard to develop agricultural production in Sichuan. He appointed special officials in charge of the ancient Dujiangyan (Dujiang Weir) and had many more water works built. To secure a peaceful environment for the kingdom, he took care to improve relations with the ethnic minorities inhabiting present-day Guizhou and Yunnan provinces and to strengthen the political, economic and cultural ties between the Han people and these ethnic minorities.
The Wei reached a higher level of cultural development than the other two states. A new sect appeared in the realm of philosophy, called xuan xue (a school of Taoism) which took the three books—Lao zi (Book of Lao Zi), Zhuang zi (Book of Zhuang Zi) and Yi jing (Book of Changes)—as its "Three Classics". The founder of this school was Wang Bi (226-49), a native of Shanyang (now Jiaozuo City, Henan) and author of Lao zi zhu (Annotations to "Book of Lao Zi"), Zhou yi zhu (Notes on the "Book of Changes") and Zhou yi lue li (A Brief Exposition of the "Book of Changes"). Wang Bi preached that Non-being was more important than Being and the world of Being took Non-being as its substance. This theory of objective idealism boiled down to "acting without striving" or "letting things take their natural courses". In other words, it aimed to relegate feudal moral codes to a secondary position and provided members of the feudal upper strata with excuses for their greediness and indulgence. An ideological reflection of the depraved life of the upper strata at that time, Wang Bi's works nevertheless had extensive influence in the history of Chinese philosophy. Cao Cao (155-220) and his sons Cao Pi (187-226) and Cao Zhi (192-232) were all great names in literature. Cao Cao's poems, A Short Song and A Stroll Out of Summer Gate, written in a plaintive style at once virile and unrestrained, rank among the most famous in Chinese poetry. The Dian lun lun wen (Historical Allusions and Essays) by Cao Pi is the earliest piece of literary criticism extant in China. The poems of Cao Zhi have left their mark on the development of the wu yan shi (poems with five characters to a line).
The relationship between the three states began with Wu and Shu joining hands against Wei. Later the two allies fell out in their scramble over Jingzhou. In 220, when Guan Yu, commander of the Shu garrison in Jingzhou, was locked in battle with the Wei forces, Wu sprang a surprise attack, captured Jingzhou and killed Guan Yu. In 222, Liu Bei led a huge force out of Shu in an expedition against Wu. A decisive battle was fought at Yiling (north of Yidu County, Hubei Province), in which the Shu troops were routed. Liu Bei died the following year, and his son, Liu Chan, succeeded to the throne with the help of Prime Minister Zhuge Liang. Zhuge Liang switched back to the earlier policy of alliance with Wu against Wei, his aim being to drive north to occupy the Central Plains and recover the cause of the Han house. But the several northern expeditions he did undertake failed. In the last expedition in 234, Zhuge Liang died on his sickbed at the front at a time when his army was fighting to a stalemate with the Wei forces under the command of Field Marshal Sima Yi at Wuzhangyuan (southwest of Meixian County, Shaanxi Province). The Shu troops then pulled back to Sichuan. From then on, Shu declined while the state power of Wei gradually passed into the hands of the Sima family. After the death of Sima Yi, his sons, Sima Shi and Sima Zhao, successively held the reins of the Wei government, relegating the Wei emperor to the status of a figurehead.
In 263, Wei vanquished Shu. Three years later, Sima Yan dethroned the Wei emperor and established the Jin Dynasty (historically known as the Western Jin), with the capital remaining at Luoyang as during the Wei Dynasty. In 280, Sima Yan, later known as Emperor Wu of Jin, defeated Wu and unified—though only for a short period—the China that had remained divided for scores of years after the end of the Eastern Han Dynasty.