淝水之戰
After Former Qin suffered a major defeat against Jin forces at the Battle of Fei River in 383 in a failed bid to unite China, it began to disintegrate, and, among others, Later Yan, with Murong Chui, the uncle of Former Yan's last emperor Murong Wei, as emperor (Emperor Wucheng), took over Former Yan's old territory and people; and Northern Wei, with Tuoba Shiyijian's grandson Tuoba Gui as prince, took over Dai's former territory and people.