However, despite the apparent Later Tang strength that the destruction of Former Shu showed, Emperor Zhuangzong's rule was actually becoming destabilized due to the soldiers' discontent toward his failure to implement his prior promises of rewards to them for their achievements in destroying Later Liang and Former Shu, and the discontent was further exacerbated by the subsequent executions of Guo and another major general, Li Jilin the Prince of Xiping by Emperor Zhuangzong and his wife Empress Liu. Thereafter, Emperor Zhuangzong's adoptive brother Li Siyuan rebelled at Daming (大名, in modern Handan, Hebei). By summer 926, another mutiny at the capital Luoyang caused Emperor Zhuangzong to die in battle. Li Siyuan subsequently declared himself emperor (as Emperor Mingzong).