慕容盛
In 389, at the age of 16, Murong Sheng was put in charge by Murong Chui of the old Former Yan capital Jicheng (modern Beijing). In 391, he was given the title of viceroy. He remained there until around the new year 396, when, in light of his father Murong Bao's defeat by Northern Wei's prince Tuoba Gui at the Battle of Canhe Slope, Murong Chui recalled Murong Sheng and his uncle Murong Long (the viceroy at another old Former Yan capital, Longcheng (龍城, in modern Jinzhou, Liaoning) back to Zhongshan with their troops, to prepare for another attack on Northern Wei. In spring 396, Murong Chui's campaign against Northern Wei was initially successful, but he then got ill and was forced to withdraw back to Zhongshan, and he died on the way. Murong Bao succeeded him.