颜真卿
Meanwhile, An had Emperor Xuanzong's sister, Princess of Huo, as well as a number of other imperial relatives, executed, and sacrificed their organs to An Qingzong. At this point, there was a new Tang Emperor: Li Heng, or Emperor Suzong. Due to the slowness of the Yan advance, the Yan forces were unable to capture either Emperor Xuanzong, who eventually reached Shu Commandery, or Li Heng, who fled to Lingwu and took the Tang imperial title there (as Emperor Suzong). (Xuanzong recognized Li Heng's actions and subsequently took the title "Taishang Huang" ("retired emperor").) Hearing news of Chang'an's fall, Guo and Li Guangbi withdrew to Lingwu, allowing Shi to again pacify the region north of the Yellow River and east of the Taihang Mountains with exception of pockets held by Yan Zhenqing and other Tang officials under his command.