with him, but at Zhang's suggestion left Li Zhi in charge at Chang'an instead, to allow Li Zhi to become more familiar with the important affairs of state in his absence. After Emperor Taizong returned from Ling Prefecture, he retained for himself the authorities over imperial worship, state guests, military, the commissioning of officers of higher than the fifth rank, and executions, and transferred all other authorities to Li Zhi. In 647, a commoner named Duan Zhichong () submitted a petition to Emperor Taizong, asking him to pass the throne to Li Zhi. Li Zhi, concerned that Emperor Taizong might be offended, was worried and grieving, and Zhangsun suggested that Duan be executed. Emperor Taizong did not take offense and did not punish Duan or Li Zhi. Meanwhile, Li Zhi began to build a Buddhist temple named Daci'en Temple () in commemoration of his mother Empress Zhangsun, and the temple was completed in 648. In 649, while at the summer palace Cuiwei Palace (翠微宮, in the Qin Mountains), Emperor Taizong was gravely ill, and he, while impressed with Li Shiji's abilities, was concerned that Li Shiji was too able and would not submit to Li Zhi. He stated to Li Zhi: He then demoted Li Shiji to the post of the commandant of Die Prefecture (疊州, roughly modern Gannan Tibetan Autonomous Prefecture, Gansu). Li Shiji, realizing what was happening, after receiving the order, departed without hesitation. As Emperor Taizong's illness was getting more serious, Li Zhi continuously attended to him and wept constantly, often going without food, which touched Emperor Taizong greatly. Emperor Taizong entrusted Li Zhi to Zhangsun and Chu Suiliang, and then died on 10 July 649. Initially, Li Zhi was so mournful that he could not carry out any actions other than holding onto the necks of Zhangsun and Chu. Zhangsun, while mourning himself, reminded Li Zhi that he was now in charge of the empire and must act accordingly. Zhangsun also ordered that Emperor Taizong's death not be announced for the time being, and then, the next day, accompanied Li Zhi back to Chang'an. Zhangsun issued several edicts in Emperor Taizong's name—including making Yu Zhining, Zhang, and Gao Jifu chancellors. Two days later, Emperor Taizong's death was officially announced. On 15 July, Li Zhi took the throne (as Emperor Gaozong). Reign as Emperor During his 34-year reign, he was unable to exercise power alone and was