An is An Lushan and Shi is Shi Siming. They were chancellors during the reign of EmperorTang Xuanzong (Li Longji). An Shi Rebellion is a turning point of Tang from extreme prosperity to weakness. During the Emperor Xuanzong, the society became very peaceful and prosperous However, the annexation of land by landlords and government officials became more and more severe. Many peasants lost farmland and became vagabonds. At the same time, the imperial family’s life was very corrupt and luxurious. Xuan Zong was crazy about Concubine Yang (named Yang Yuhuan). He was drowned in singing, dancing, drinking and beauties. He put the treacherous official Li Linfu in the very important position and believed Yang’s brother Yang Guozhong. Li Linfu and Yang Guozhong were more and more powerful, which were envied by Shi Siming and An Lushan. Then, the inside of the ruling classes appeared conflicts. What’s more, since Xuan Zong, the mercenary system (conscription) had been complimented. The soldiers serving the central government were all conscripted from the local barracks. In this process, many soldiers were embraced by the local warlords. When the conflicts between the central government and the local warlords were more and more conspicuous, Shi Siming and An Lushan took advantage of the local warlords to fight against the Tang movement. Additionally, An and Shi hooked in the ethnic minorities living in Youzhou, north of Hebei to fight against the Tang.