Background During the
Three Kingdoms period, the
Sima clan—with its most accomplished individual being
Sima Yi—rose to prominence within the kingdom of
Cao Wei that dominated northern China. Sima Yi was the
regent of Cao Wei, and in 249 he instigated a coup d'état known as the
Incident at the Gaoping Tombs, after which the Sima clan began to surpass the imperial Cao clan's power in the kingdom. After Sima Yi's death in 251, Sima Yi's eldest son
Sima Shi succeeded his father as regent of Cao Wei, maintaining the Sima clan's tight grip on the Cao Wei political scene. After Sima Shi's death in 255, Sima Shi's younger brother
Sima Zhao became the regent of Cao Wei. Sima Zhao further assisted his clans' interests by suppressing rebellions and dissent. In 263, he directed Cao Wei forces in conquering
Shu Han and capturing
Liu Shan (the son of
Liu Bei), marking the first demise of one of the Three Kingdoms. Sima Zhao's actions awarded him the title of King of Jin, the last achievable rank beneath that of emperor. He was granted the title because his ancestral home was located in
Wen County, on the territory of the
Zhou-era
state of Jin, which was centered on the Jin River in
Shaanxi. Sima Zhao's ambitions for the throne were visible, but he died in 265 before any usurpation attempt could be made, passing the opportunity to his ambitious son
Sima Yan.
Western Jin (266–316) Founding and unification The Jin dynasty was founded by Sima Yan, who became known as Emperor Wu (the "Martial Emperor of Jin"). After succeeding
his father as the King of Jin and regent of
Cao Wei in 265, Sima Yan declared himself emperor of the Jin dynasty on 4 February 266 and forced the final Wei ruler
Cao Huan to abdicate. Following the unification, China entered a decade of peace and economic prosperity, with accounts detailing the extravagant and outlandish lifestyles of the aristocracy. Internally, Emperor Wu upheld
Confucian primogeniture by decreeing that his eldest son, Sima Zhong, posthumously known as
Emperor Hui, would succeed him to the throne, despite his apparent
developmental disability. To protect his heir and dynasty, he empowered his princes and dukes by appointing them to important military and administrative positions. Meanwhile, a few officials also began expressing concerns regarding the growing population and treatment of the various non-Han peoples ("
Five Barbarians") that had been resettling in northern China for centuries.
Decline Emperor Wu died in 290, and Emperor Hui's ascension began the
War of the Eight Princes. In 291, Emperor Hui's wife,
Empress Jia, seized power and began ruling the empire behind her husband's throne. Under her rule, the affluence of the aristocracy went unchecked, and corruption ran rampant within the government. She and her family were overthrown in a coup in 300, but a series of civil wars soon broke out between the Sima princes for the regency and succession of Emperor Hui, devastating most of northern China and the imperial military. The short-lived unification of China came to an end in 304; that year, the
Cheng-Han and
Han-Zhao declared their independence from Jin. The
Upheaval of the Five Barbarians carried on the chaos from the War of the Eight Princes, as uprisings and famines continued to erode Jin authority in the north. In 311, the Jin capital
Luoyang was
sacked by Han-Zhao forces under
Liu Cong, and Sima Chi, posthumously known as
Emperor Huai, was captured and later executed. Emperor Huai's successor Sima Ye, posthumously known as
Emperor Min, was then also captured and executed by Han-Zhao when they seized
Chang'an (present-day
Xi'an) in 316, marking the end of the Western Jin.
Eastern Jin (317–420) , 484 CE. Untypical of the
Northern Wei style, it was probably brought from the court of the Jin dynasty by Sima Jinlong's father. Alternatively, it could be a Northern Wei work strongly influenced by Jin artistic styles, such as the work of
Gu Kaizhi.
Establishment After the fall of
Chang'an and the execution of
Emperor Min of Jin, Sima Rui, posthumously known as
Emperor Yuan, was enthroned as Jin emperor in 318. He reestablished the Jin government at
Jiankang (modern
Nanjing), which became the dynasty's new capital and marked the beginning of the Eastern Jin period. Since one of Sima Rui's titles was the prince of
Langya, the newly established
northern states, which denied the legitimacy of his succession, sometimes derisively referred to his empire as "Langya". The Eastern Jin period saw the peak of
menfa ( 'gentry clan') politics. The authority of the emperors was limited, while national affairs were controlled by powerful immigrant elite clans like the Wang () clans of
Langya and
Taiyuan, the Xie () clan of
Chenliu, the Huan () clan of
Qiao Commandery, and the Yu () clan of
Yingchuan. Among the people, a common remark was that "
Wang Dao and
Sima Rui, they dominate the nation together" (). Particularly in the
Jiangnan region,
Celestial Masters and the nobility of northern China subdued the nobility of southern China during the Jin dynasty. Southern China overtook the north in population due to depopulation of the north and the migration of northern Chinese to southern China. Different waves of migration of aristocratic Chinese from northern China to the south at different times resulted in distinct groups of aristocratic lineages.
Demise In 403,
Huan Xuan, the son of esteemed general
Huan Wen, usurped the Jin throne and declared the dynasty of
Huan Chu. Huan Xuan was soon toppled by
Liu Yu, who reinstated Jin rule by installing Sima Dezong on the throne, posthumously known as
Emperor An. Meanwhile, the civilian administration suffered, as there were further revolts led by Sun En and Lu Xun, and
Western Shu became an independent kingdom under
Qiao Zong. In 419, Liu Yu had Sima Dezong strangled and replaced by his brother Sima Dewen, posthumously known as
Emperor Gong. Finally, in 420, Sima Dewen abdicated in favour of Liu Yu, who declared himself the ruler of the new
Song dynasty (which is referred to as the Liu Song dynasty by historians in order to prevent confusion with the
Song dynasty established in 960). Sima Dewen was then asphyxiated with a blanket in the following year. In the north,
Northern Liang, the last of the
Sixteen Kingdoms, was conquered by
Northern Wei in 439, ushering in the
Northern dynasties period. The Xianbei
Northern Wei accepted the Jin refugees () and (). They both married Xianbei princesses. Sima Fei's wife was named Huayang (), who was a daughter of
Emperor Xiaowen; Sima Chuzhi's son was
Sima Jinlong, who married a
Northern Liang princess who was a daughter of the
Lushuihu king
Juqu Mujian. More than fifty percent of Tuoba Xianbei princesses of the Northern Wei were married to southern Han Chinese men from the imperial families and aristocrats from southern China of the
Southern dynasties who defected and moved north to join the Northern Wei. Much later,
Sima Guang (1019–1086), who served as
chancellor for the
Song and created the comprehensive history
Zizhi Tongjian, claimed descent from the Jin dynasty (specifically,
Sima Fu, brother of
Sima Yi). == Government and demography ==