 Later in 757, when Emperor Xuanzong's son Emperor Suzong had taken over as emperor, a joint Tang and Huige army recaptured Chang'an and Luoyang from Yan, then under the rule of An Lushan's son An Qingxu (An Lushan having been assassinated by An Qingxu earlier in the year).An Qingxu fled to Yecheng and put up his defense there.A number of Tang generals, including, in addition to Dong Qin, Guo Ziyi, Lu Jiong (), Li Huan (), Xu Shuji (), Li Siye, Ji Guangchen (), Cui Guangyuan (), Li Guangbi, and Wang Sili (), converged on Yecheng and put it under siege, although Tang forces were unable to capture Yecheng quickly.