The following year, An Lushan's army marched westward, and Emperor Xuanzong was forced to leave Beijing. In Maweipo, soldiers who marched westward defected and killed Yang's brother and sister. The historical truth of this mutiny has always been a topic of active discussion in historians, and many scholars have done very in-depth research. Some scholars believe that this is an unplanned mutiny with no mastermind behind it. The soldiers marched all night, hungry, and launched a mutiny under the leadership of General Chen of Longwu, in order to protect themselves. This statement lacks credibility and is just a phenomenon. Chen, as a general of an empire, can't launch this mutiny. His power is limited and he doesn't have enough political motives. Probably hungry enough to start a mutiny. Other scholars believe that eunuch Gao is the mastermind behind the mutiny. Mr. Huang Yongnian, a scholar in Tang Shi, pointed out that Gao Lishi was an influential official in the Tang Xuanzong period. After Sun Chang Wuji and Chu Suiliang were executed by Emperor Gaozong in the Tang Dynasty, foreign prime ministers could not get their hands on the palace regime, and their power was generally limited to daily government affairs.