in modern Baoji, Shaanxi) and killed him and forced Emperor Xuanzong to kill Consort Yang as well. Emperor Xuanzong then poised to continue to head toward Jiannan. The people in the Mawei region tried to persuade Emperor Xuanzong not to continue on—believing that Chang'an could be recaptured. Emperor Xuanzong asked Li Heng to try to comfort the people. Once Li Heng left Emperor Xuanzong's presence, however, Li Fuguo and Li Heng's sons Li Tan the Prince of Jianning and Li Chu the Prince of Guangping, persuaded Li Heng not to follow Emperor Xuanzong to Jiannan—arguing that with the physical barriers between Chang'an and Jiannan, that once they had left the region, Chang'an could no longer be captured. Li Heng agreed and had Li Chu report this to Emperor Xuanzong. Emperor Xuanzong agreed with Li Heng's decision, but he himself continued on to Jiannan. Li Heng, escorted by a small number of guard soldiers commanded by Li Tan, then headed to the border city of Lingwu. With the army at Lingwu pressuring him to take imperial title, Li Heng declared himself emperor on August 13 (as Emperor Suzong). When news of this reached Emperor Xuanzong in Jiannan, Emperor Xuanzong recognized Emperor Suzong as emperor and took the title of Taishang Huang (retired emperor), although he continued to exercise some imperial authority—including, for example, issuing an edict that posthumously honored Emperor Suzong's mother Consort Yang as Empress Yuanxian. (Some historians, including the modern historian Bo Yang, believed that Emperor Xuanzong's continued issuance of edicts, while not on the surface conflicting with Emperor Suzong's authority, caused Emperor Suzong pressure to try to recapture Chang'an as quickly as possible to avoid any contention for the throne—either in the form of Emperor Xuanzong himself resuming imperial authority or in the form of another imperial prince rising to defeat Yan.) Reign Emperor Suzong, once he became emperor, set his eyes on recapturing Chang'an from Yan forces, as Yan forces faced heavy resistance from the people of the Guanzhong region (i.e., the region around Chang'an) and was not able to keep the region under firm control. (By this point, An Lushan had been assassinated and succeeded by his son An Qingxu, as the emperor of Yan.) However, an immediate attempt to do so, commanded by the chancellor Fang Guan, was defeated by the Yan forces near Chang'an with heavy losses. Meanwhile, around the same time, Emperor Suzong's