赵延寿
In 946, there were rumors that the major Liao general Zhao Yanshou—who had previously been a major Later Tang general before being captured by the Khitan in the campaign that led to Later Tang's destruction—was planning on defecting to Later Jin. This rumor was believed by Li Song and Feng, who then served as Shi's chief of staff. They had Du write a letter to Zhao, encouraging him to do so, with the officer Zhao Xingshi (), who had previously served under Zhao Yanshou, delivering the letter. Zhao Yanshou wrote back (to try to lead Later Jin forces into a trap), stating, "I have long been in a foreign land, and I want to return to China. Please launch a major army to support me, so that I can pull myself out and return with it." Subsequently, under Emperor Taizong's orders, Liao's prefect of Ying Prefecture (瀛州, in modern Cangzhou), Liu Yanzuo (), also offered to defect to Later Jin. Shi thus put Du and Li Shouzhen in command of an army to attack north, with the stated objectives being to first recapture the prefectures Shi Jingtang previously ceded to Liao (the Sixteen Prefectures), and then to destroy Liao. (Zhao Ying, however, had reservations, pointing out that Du, despite his honored position, was still often dissatisfied with his station, and therefore suggested to Li Song and Feng that Li Shouzhen be put in command by himself; Zhao Ying's suggestions were not listened to, however.) When Du and Li Shouzhen advanced, though, they were met by a large army that Emperor Taizong personally commanded. The Liao army eventually surrounded the Later Jin army at Zhongdu Bridge (中度橋, in modern Baoding). After Emperor Taizong made the promise to Du to make "him" emperor if he surrendered, Du and Li Shouzhen surrendered their army. (As part of accepting Du's surrender, Emperor Taizong had Zhao mockingly put an imperial robe on Du.) Emperor Taizong then prepared to advance south. He commissioned Li Shouzhen "'Situ" (司徒, one of the Three Excellencies) as well as continuing to the military governor of Tianping, and had Li Shouzhen and Du accompany him south. With virtually the entire Later Jin army having been given to Du and Li Shouzhen for this northern campaign, Kaifeng was left essentially defenseless, and Shi felt compelled to surrender, ending Later Jin. Emperor Taizong subsequently entered Daliang.