In 712, Emperor Ruizong passed the throne to Li Longji, who took the throne as Emperor Xuanzong, but retained power as
Taishang Huang (retired emperor). Subsequently, Guo Yuanzhen was made the commandant of the forces of the Suofang region (i.e., modern
Ningxia and northern
Shaanxi) and the minister of defense (兵部尚書,
Bingbu Shangshu). In 713, he was again made chancellor with the designation
Tong Zhongshu Menxia Sanpin (). As of 713, Emperor Xuanzong and Princess Taiping were locked into a power struggle. It was said that Princess Taiping,
Dou Huaizhen,
Cen Xi,
Xiao Zhizhong,
Cui Shi; along with other officials
Xue Ji, Li Jin () the Prince of Xinxing (a grandson of Li Deliang (), a cousin of Tang's founder
Emperor Gaozu), Li You (), Jia Yingfu (), Tang Jun (); the generals Chang Yuankai (), Li Ci (), and Li Qin (); and the monk Huifan (), were plotting to overthrow Emperor Xuanzong. It was further said that they discussed, with the
lady-in-waiting Lady Yuan to poison the
gastrodia elata that Emperor Xuanzong routinely took as an aphrodisiac. When this alleged plot was reported to Emperor Xuanzong by
Wei Zhigu, Emperor Xuanzong, who had already received advice from Wang Ju (),
Zhang Shuo, and
Cui Riyong to act first, did so. He convened a meeting with his brothers Li Fan () the Prince of Qi, Li Ye () the Prince of Xue, Guo, along with a number of his associates — the general Wang Maozhong (), the officials Jiang Jiao () and Li Lingwen (), his brother-in-law Wang Shouyi (), the
eunuch Gao Lishi, and the military officer Li Shoude () — and decided to act first. On July 29, Emperor Xuanzong had Wang Maozhong take 300 soldiers to the imperial guard camp to behead Chang and Li Ci. Then, Jia, Li You, Xiao, and Cen were arrested and executed as well. Dou and Princess Taiping committed suicide. When Emperor Ruizong heard about the incident, he ascended the tower at Chengtian Gate () to try to ascertain what was happening, and it was Guo who informed him what happened. Emperor Ruizong subsequently yieldedpowers to Emperor Xuanzong and no longer actively participated in policy decisions thereafter. It was said that during the crisis, Guo spent 14 nights at the legislative bureau (中書省,
Zhongshu Sheng) without returning home. For his contributions, he was created the Duke of Dai and awarded silk, and further given the additional post as chief imperial censor (御史大夫,
Yushi Daifu). In winter 713, when Emperor Xuanzong was examining the troops, he was angry that the troops were disorganized, and he had Guo and the official Tang Shao () arrested and ordered them executed, in order to try to show his power—but did not actually intend to kill them. However, the general Li Miao () executed Tang and was set to execute Guo, when fellow chancellors
Liu Youqiu and Zhang Shuo kneeled and begged forgiveness on Guo's part, pointing out Guo's great contributions. Emperor Xuanzong thus exiled Guo to Xin Prefecture (新州, roughly modern
Yunfu,
Guangdong). He soon moved Guo to be the military advisor to the prefect of Rao Prefecture (饒州, roughly modern
Shangrao,
Jiangxi), but Guo, depressed over his exile, died on the way. == Notes ==