Why was there chaos in the north during the Sixteen Kingdoms period and the Eastern Jin Dynasty still not unified?

At the end of the Western Jin Dynasty, the world was in chaos. In order to escape the war, a large number of northern gentry, literati and ordinary people left their homes and fled to the south. This event is called "crossing the south with a crown" in history.

In 3 16 AD, Liu Yao, a Xiongnu aristocrat, led an army to attack Chang 'an, and the Western Jin Dynasty perished. The following year, Si Marui, the former king of Langya in the Western Jin Dynasty, who "crossed the south" to Jianye (now Nanjing) in advance, declared himself emperor. Historically, this regime established by Si Marui in the south was called the Eastern Jin Dynasty.

The Eastern Jin Dynasty lasted 103, and at the same time, the sixteen countries occupied the Central Plains. Compared with the Sixteen Countries, the Eastern Jin regime was relatively stable and there was no major division. However, it is puzzling that although many regimes in the Central Plains struggled with each other and made a mess, the rulers of the Eastern Jin Dynasty did not seize the opportunity to recover their homeland. Although several northern expeditions were organized during the period, they all made a scene, with little rain and no joy. Then the question is, why can't the Eastern Jin Dynasty unify the whole country?

At the beginning of the founding of the Eastern Jin Dynasty, most of the ruling classes came from the north. In the eyes of families in the south, these northerners, including Si Marui, are hostile "invaders", so it is conceivable that the ruling class was hostile to the south at that time. In the end, Prime Minister Wang Dao, on behalf of the Northern Immigration Group, successfully persuaded most influential southern families to support the new regime on the condition of high officials and generous salaries. Driven by these deep-rooted families, other southern elites also catered to them, and the Eastern Jin regime gained a firm foothold in the south.

However, for the rulers of the Eastern Jin Dynasty, reconciliation with the southern families was only the first step in a thousand difficulties. In 322 AD, Wang Dun (cousin Wang Dao), who controlled the middle reaches of the Yangtze River, launched a rebellion, led troops into Beijing and took control of the imperial court. Two years later, Wang Dun died, and Sima's family regained the imperial power.

In 327 AD, the Soviet army, the general in charge of defending the Huaihe River in the Eastern Jin Dynasty, rebelled and once occupied the capital and controlled the imperial court. Later, under the crusade of Tao Kan, Soviet soldiers were defeated and killed. Because of his outstanding performance in counterinsurgency, Tao Kan became an extremely important official and the actual controller in the middle reaches of the Yangtze River.

In 347 AD, Huan Wen, who was born in a military family, led an army up the river, attacked and destroyed the Chenghan regime that occupied Shu. This victory has brought Huan Wen extraordinary prestige. In the next twenty years, Huan Wen took control of southern politics.

As can be seen from the above events, although the Sima family was nominally the supreme ruler of the Eastern Jin Dynasty, the generals of the military group had a great voice in the court, and the emperor became the weak side in many cases.

After Huan Wen came to power, the Eastern Jin Dynasty entered a relatively stable period. At this time, some people in the court began to propose to recover the homeland of the northern Central Plains. However, this proposal has caused great controversy. First of all, the aristocratic families who originally went south from the north have reached the second and third generations. They live in a comfortable manor in the south and hold important leisure positions in the court. For these "second generation of officials" and "third generation of officials", the so-called homeland of the Central Plains is only a concept in books, and there is no local complex. Therefore, whether to carry out the northern expedition with the strength of the whole country is a problem that needs to be discussed.

More importantly, supporting the Northern Expedition is bound to give the generals of the military group headed by Huan Wen more power. Once the Northern Expedition is successful, the prestige of Huan Wen and others will be above the imperial power, and unifying the whole country will mean disaster for the present imperial court. Even if the Northern Expedition fails, generals with "swords and handles" will have the hidden danger of launching rebellion and establishing a military dynasty. Therefore, the vast majority of civil servants from the emperor to the court are strong opponents of the proposal of the Northern Expedition to recover the Central Plains.

In fact, everyone's worries are not groundless. After Huan Wen came to power, he showed excessive enthusiasm for the Northern Expedition. With his fame and status at that time, I'm afraid no one can stop his road to hegemony if he wins a big victory. The imperial court knew Huan Wen's idea, but did not dare to impose obstacles, so it took a delaying attitude.

Later, Huan Wen still led by its own strength and launched three northern expeditions. However, due to the lack of knowledge in the Eastern Jin Dynasty, the strength of the Northern Expedition was greatly reduced, and the three northern expeditions failed to achieve the expected purpose, thus damaging Huan Wen's reputation, and his ambition to seize the throne failed to be realized after all.

It can be seen from the Huan Wen incident that the Northern Sixteen Countries Rebellion was not that the Eastern Jin Dynasty did not have the opportunity or strength to unify the whole country, but that no one in the imperial court was willing and supported the Northern Expedition except the military clique. If the price of recovering the homeland of the Central Plains is the change of ownership, what is the significance of unifying the whole country for the ruling class in the Eastern Jin Dynasty?