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. During Murong Bao's reign Murong Bao then faced a succession issue. Murong Hui, now the Duke of Qinghe, was most favored by Murong Chui and considered the most capable, and when Murong Chui waged his last campaign, he put Murong Hui in charge of Longcheng. As Murong Chui was on his deathbed, he further told Murong Bao to make Murong Hui his crown prince, but Murong Bao favored his young son Murong Ce () the Duke of Puyang, and did not favor Murong Hui. Murong Sheng, who was slightly older than Murong Hui, also did not want Murong Hui to be crown prince, and so also encouraged Murong Bao to create Murong Ce crown prince. Murong Bao did so in fall 396, and created Murong Hui and Murong Sheng princes (in Murong Sheng's case, the Prince of Changle). Murong Hui was displeased and secretly considered rebellion. Later in 396, Northern Wei launched a major attack on Later Yan, quickly taking Bing Province (并州, modern central and northern Shanxi) and then descending on Zhongshan, putting it under siege. In spring 397, after being unable to force Northern Wei to lift its siege and after Murong Bao's brother Murong Lin the Prince of Zhao rebelled, Murong Bao decided to abandon Zhongshan and flee to Longcheng. Murong Sheng followed his father in joining his brother Murong Hui's army, which had advanced south from Longcheng. Later that year, after Murong Hui killed Murong Long and severely wounded another uncle, Murong Nong, in an attempted coup to force Murong Bao to create him crown prince, Murong Hui was defeated and killed. Meanwhile, Murong Sheng became one of the major generals. In 398, against Murong Sheng's and Murong Nong's advice, Murong Bao insisted on launching another campaign to try to regain territory lost to Northern Wei, putting Murong Sheng in charge of Longcheng as he departed. The tired troops mutinied on the way, forcing him to return to Longcheng to defend it with Murong Sheng, but when Murong Nong then inexplicably surrendered to the rebels, Longcheng