慕容皝
That same year, Murong Huang, countering his father's prior policy of having no contact at all with Jin's rival Later Zhao, sent messengers to Later Zhao promising to be a vassal and requesting a joint attack against the Duan. Later Zhao's emperor Shi Hu was very pleased, and they agreed on an attack in 338. In the spring, they launched the attacks. Murong Huang quickly attacked and pillaged the Duan cities north of its capital Lingzhi (令支, in modern Tangshan, Hebei), defeating Duan Lan's forces. He then withdrew, and when Later Zhao forces arrived, Duan Liao no longer dared to face them but instead abandoned Lingzhi and fled. Lingzhi surrendered to Later Zhao. Shi Hu was happy about the victory but angry that Murong Huang withdrew before the armies could meet, and he decided to turn his armies against Murong Huang instead. With Later Zhao's massive armies arriving in Former Yan territory, nearly all of the cities submitted to Later Zhao except the capital Jicheng. Murong Huang considered fleeing, but under advice of his general Muyu Gen, he stayed and defended the city for nearly 20 days, and Later Zhao forces were forced to withdraw; Murong Huang then sent his son Murong Ke to attack the retreating Later Zhao troops, scoring a great victory, and the only Later Zhao force remaining intact was that of Shi Min, Shi Hu's adopted grandson. After Later Zhao's withdrawal, Murong Huang recaptured the cities that had rebelled. He also took over cities formerly ruled by the Duan, extending into modern northern Hebei. In early 339, after Duan Liao sent conflicting requests to Later Zhao and Former Yan, requesting surrender, the Later Zhao and Former Yan forces engaged, and Murong Ke again won a great victory over Later Zhao. Murong Huang honored Duan Liao as a guest and merged Duan's remaining forces into his own. Later that year, however, Duan planned a rebellion and was killed by Murong Huang. (However, the Duan clan was not wiped out, and many members of the Duan clan later served as generals, officials, and imperial consorts of the Murongs.) From this point on, Former Yan forces would conduct yearly raids against Later Zhao's border region. They would also periodically attack the Yuwen tribe and Goguryeo.