Zhaoyi. In fall 844, the three eastern prefectures surrendered to He Hongjing and Wang Yuankui, and soon thereafter, Liu Zhen was killed by his own officer Guo Yi (), who then surrendered. After the Zhaoyi campaign After the Zhaoyi campaign, Li Deyu used the opportunity to carry reprisals against his political enemies in the Niu-Li Factional Struggles—those who were members of what would later be referred to as the Niu Faction (named after Niu Sengru) against Li Deyu's Li Faction—including the former chancellors Niu Sengru and Li Zongmin—by accusing them of complicity in Liu Zhen's rebellion. As a result, Niu and Li Zongmin were exiled to remote regions. In 845, Emperor Wuzong wanted to create his favorite concubine, Consort Wang, empress. Li Deyu, pointing out that Consort Wang was of low birth and that she was sonless, opposed. Emperor Wuzong therefore did not do so. (Emperor Wuzong had five known sons, but very little is known about them other than their names and their princely titles.) Late in Emperor Wuzong's life, he began taking pills made by Taoist alchemists, which were intended to lead to immortality, and it was said that his mood became harsh and unpredictable as a side effect. By late 845, he was seriously ill. In early 846, in an attempt to ward off the illness, he changed his name to Li Yan—under the theory that under the Wu Xing cosmology, his original name of Chan () contained two instances of earth () while only containing one instance of water (), which meant that he was getting suppressed by the dynasty's own spirits (as Tang beliefs included that the dynasty was protected by earth), while Yan () contained two instances of fire (), which was more harmonious with earth. Despite this change, his conditions did not get better. The eunuchs, believing that Emperor Wuzong's uncle Li Yi the Prince of Guang to be simple-minded, decided to make him Emperor Wuzong's successor; they therefore had an edict issued in Emperor Wuzong's name creating Li Yi crown prince (and changing Li Yi's name to Li Chen). Soon thereafter, Emperor Wuzong died, and Li Chen took the throne as Emperor Xuānzong. Chancellors during reign Yang Sifu (840) Li Jue (840) Cui Dan (840–841) Cui Gong (840–843) Li Deyu (840–846) Chen Yixing (841–842) Li Shen (842–844) Li Rangyi (842–846) Cui Xuan (843–845) Du Cong (844–845) Li Hui (845–846) Zheng Su (845–846)