杨国忠
However, the geographical features of the terrain were not the only hardships on the journey: there was a matter that first had to be settled, involving the relationship between Xuanzong and the Yang family, especially the emperor's beloved Yang Guifei. So, before progressing more than a few kilometers along the way, an incident occurred at Mawei Inn, in today's Xingping in Xianyang, Shaanxi. Xuanzong's bodyguard troops were hungry and tired, and very angry with Yang Guozhong for exposing the whole country to danger. They demanded the death of the much-hated Yang Guozhong, and then of his cousin and imperial favorite, Yang Guifei. Soon the angry soldiers killed Yang Guozhong, Yang Xuan (his son), Lady Han and Lady Qin (Yang Guifei's sisters). With the army on the verge of mutiny, the Emperor had no choice but to agree, ordering the strangling of Lady Yang. The incident made Xuanzong fear for his own safety, so he fled to Chengdu at once. However, people stopped his horse, not wanting him to go away. So he made the crown prince, Li Heng, stay to hold the fort. Instead, Li Heng fled in the other direction to Lingzhou (today called Lingwu, in Ningxia province). Later, on 12 August, after reaching Sichuan, Xuanzong abdicated (becoming "Taishang Huang"), in favor of the crown prince, who had already been proclaimed emperor.