Liu Yu's expeditions were a series of successful campaigns mounted by Jin China from 409 CE

Common Era

Common Era ,abbreviated as CE, is an alternative designation for the calendar era originally introduced by Dionysius Exiguus in the 6th century, traditionally identified with Anno Domini .Dates before the year 1 CE are indicated by the usage of BCE, short for Before the Common Era Common Era...

 to 416 CE against Southern Yan, Later Qin, Northern Wei and Xia that successfully recovered all of China's territory south of the Yellow River with the exception of the Chang'an area(which was taken by Xia). This victories were the basis of the prosperity of the Reign of Yuanjia

Reign of Yuanjia

The reign of Yuanjia was a period in Chinese history under the Liu Song Dynasty which was comparatively wealthy and stable compared to previous and later periods. It occurred under the diligent Emperor Wen of the Liu Song dynasty, who was an able administrator...

Background

Following Jin's victory at the Battle of Fei River

Battle of Fei River

The Battle of Fei River or “Feishui” was a battle in 383, where Fu Jiān of the Di Former Qin Empire was decisively defeated by the numerically inferior Jin army of Eastern Jin....

, North China collapsed into a plethora of barbarian states. After Liu Yu, one of the most excellent generals of the Northern and Southern dynasties period, came to power in Jin, Liu Yu saw the opportunity to recover China's heartland territories under barbarian rule.

1st expedition against Southern Yan

Liu Yu's first expedition was against Southern Yan in 409 CE. The Jin army attacked from Nanjing to Xiapei, and then to Longchen. Along the roads, Jin's forces built fortresses to prevent Southern Yan forces from cutting off their supplies. By May, Jin forces reached the Southern Yan capital at Guangdu. When he reached the area, Liu Yu saw that the ground was covered with grain and he said to his men that: "The Southern Yan ruler is already in my hand", as there would be no supply problems. In February 410 CE, Jin forces captured Guangdu and put an end to Southern Yan.

2nd expedition against Later Qin

In 416 CE, Liu Yu launched a major attack against Later Qin, defeating its general, Yao Shao. After this victory, Liu Yu recovered Luoyang, the former capital of the Jin Dynasty and was crowned Duke of Song. To complete his victory, he sent two armies into Shaanxi to engage the remnants of Later Qin's forces.

On their way there, the Jin forces were harassed by Northern Wei cavalry, who attacked the Jin forces' supply routes. In a major engagement, Jin forces defeated Northern Wei forces using crossbows to launch spears through the Wei forces, frightening them and reputedly killing some 30,000 Wei soldiers. Following this victory, Jin forces continued on Later Qin and captured its capital Chang'an, destroying it.

Loss of Chang'an region

Following this victory, it seemed that Jin would quickly destroy Xia, Northern Wei and the remaining barbarian states, reunifying China. However, Liu Yu went back to Nanjing on rumors of the death of Emperor An of Jin, leaving his general Wang Zhen'en in charge. Xia forces took the opportunity to attack, and captured the Chang'an region from Jin. Nevertheless, Jin still held most of China's territory south of the Yellow river, the traditional heartland of China.

Aftermath

These victories laid the foundation for the Reign of Yuanjia

Reign of Yuanjia

The reign of Yuanjia was a period in Chinese history under the Liu Song Dynasty which was comparatively wealthy and stable compared to previous and later periods. It occurred under the diligent Emperor Wen of the Liu Song dynasty, who was an able administrator...

, a period of relative prosperity as the Chinese heartlands fell under native rule rather than be subject to barbarian invasion and warfare.