In 1030, Xingliao and its Jurchen and Goryeo allies were defeated by a Liao pincer attack led by Punu. One of Da Yanlin's officers, Yang Xiangshi, betrayed him and opened the Eastern Capital's gates to the Khitans.
The alliance between Xingliao, its Jurchen, and Goryeo forces was crushed in 1030 when they were caught off guard by a Liao-led pincer attack led by Punu. A betrayal from one of Da Yanlin's officers, Yang Xiangshi, allowed the Khitans to breach the Eastern Capital's defenses.