User:Zrnstnsr/Conquest of Later Qin by Jin

The Conquest of Later Qin by Jin, also known as Liu Yu's conquest of Later Qin, was a military campaign launched by Jin dynasty against the state of Later Qin during the Sixteen Kingdoms period of Chinese history. It was the latter of two northern expeditions and also the final major military campaign launched by Liu Yu, the regent of Jin. The campaign culminated in fall of Later Qin and restoration of all territory south of the Yellow River. It also marked the first time that Jin recovered Guanzhong since 316, which, however, was invaded and occupied by state of Hu Xia in 418.

Decline of Later Qin
Former Qin, a Di-led state and also one of the sixteen kingdoms, unified northern China in 376. However, following the devastating defeat at Fei River, the state came to a total debacle with numerous warlords establishing their own states, one of which was Later Qin. Later Qin managed to defeat remnants of Former Qin and occupied Guanzhong and Hetao by 394. The emperor of Later Qin, Yao Xing, was ambitious and the early 5th century saw a large expansion of the state's territory. By 402, Later Qin conquered Western Qin and Later Liang, and other states near it was forced to submit to him.

However, starting from his defeat at Chaibi, the state began to decline. In 409, two states was independent from Later Qin, including Hu Xia, which seized Hetao in the north of Later Qin's territory. Xia continued to advance against Later Qin, and by 416 Xia had invaded further to Shanggui, just to the west of Chang'an.

Despite the crisis from Xia, the royal clan of Later Qin failed to unite. Yao Xing's eldest son, Yao Hong, was appointed as the crown prince in 402, while he was not favoured by his father. Consequently, many of Yao Xing's sons coveted the throne. In March 416, Yao Xing was heavily illed and his third son, Yao Bi, who seized military power before, attempted to launch a military coup to usurp the throne believing Yao Xing had died. The coup failed when Yao Xing appeared and ordered Yao Bi to suicide. Even after Yao Hong's succession, some members of the royal clan still coveted the throne and schemed a rebellion.

Rise of Liu Yu
Liu Yu was initially a soldier in Liu Laozhi's army and promoted due to his bravery and achievement. After Huan Xuan seized the power of Jin, Liu Laozhi committed suicide in fear and Liu Yu pretended to surrender to Huan while he schemed an uprising against Huan. Following Huan's usurpation, Liu revolted at Jingkou and expelled Huan out of Jiankang, who was later killed in Yi Province.

After Huan's death, Liu defeated numerous warlords inside the dynasty. He defeated Sima Xiuzhi, who was the final major warlord and fled to Later Qin later in 415. Having unified the forces in the dynasty, Liu began to aim at the northern expedition. Liu had launched a northern expedition in 410 when he destroyed the state of Southern Yan, but he was interrupted by Lu Xun uprising.

Course
On September 18, 416, the court of Jin dynasty declared an amnesty, and on the following day Liu began to launch his campaign.