Southern and Northern Dynasties - Background

Background

After the collapse of a united China under the Han dynasty in 220 due in large part to the Yellow Turban and Five Pecks of Rice rebellions, China eventually coalesced into the Three Kingdoms. Of these Three Kingdoms, Cao Wei was the strongest followed by Eastern Wu and Shu Han, but they were initially in a relatively stable formation. After a 249 coup by Sima Yi, the Sima family essentially controlled Cao Wei and soon conquered Shu Han. Following a failed coup by the ruling Cao family against the Sima family, the final Cao ruler abdicated. Sima Yan then founded the Jin Dynasty and in 280 conquered Eastern Wu, ending the Three Kingdoms and uniting China again.

The Jin Dynasty was severely weakened after the War of the Eight Princes from 291 to 306. During the reigns of Emperor Huai of Jin and Emperor Min of Jin, the country was put into grave danger with the uprising of the northern non-Han barbarians collectively known as Wu Hu. Invading barbarian armies almost destroyed the dynasty in the Disaster of Yongjia, which was the 311 sack of Luoyang. Chang'an met a similar fate in the year 316. However, a scion of the royal house, the Prince of Langya (Sima Rui), fled south of the Huai River to salvage what was left in order to sustain the empire. Cementing their power in the south, the Jin established modern-day Nanjing (then called Jianye and renamed Jiankang) as their new capital, renaming the dynasty as the Eastern Jin (317–420) since the new capital was located southeast of Luoyang. In the north, the barbarians established numerous kingdoms, leading to the period being known as the Sixteen Kingdoms. Eventually, the Northern Wei conquered the rest of the northern states in 386. Although the Chinese of the Eastern Jin (and successive southern dynasties) were well-defended from the northern barbarians by placement of naval fleets along the Yangtze River, there were still various problems faced with building and maintaining military strength. The designation of specific households for military service in the Tuntian system eventually led to a falling out in their social status, causing widespread desertion of troops on many occasions. Faced with shortage of troop numbers, Jin generals were often sent on campaigns to capture non-Chinese tribesman in the south in order to draft them into the military. The Eastern Jin Dynasty fell not because of external invasion, though, but because the general Liu Yu seized the throne from Emperor Gong of Jin, becoming Emperor Wu of Liu Song (reigned 420–422), starting the Southern and Northern Dynasties period.