Reasons for overthrowing Wu Zetian
Wu Zetian was fierce in his early years and had a good grasp of the country's military, political and economic affairs. However, in her later years, she was extremely fond of Toy Boy, indulged in pleasure all day, and was basically indifferent to state affairs, so it was easy to have an accident. Even though the brothers Toy Boy, Zhang Changzong and Zhang Yizhi brought trouble to the palace, they interfered in state affairs. Now Li Tang and Gu Wu know their ambitions. I want to get rid of these two Toy Boy.
Dragon coup
Zhang Jianzhi is very reluctant to see a great country destroyed by two Toy Boy. He thought for a moment, compared with personal interests, the country must be more important. He hated Wu Zetian's absurd actions in his later years and Toy Boy's domination of state affairs, so he launched the Dragon Coup.
One night, Wu Zetian was seriously ill. Zhang Jianzhi killed Zhang Changzong and Zhang Yizhi in Wu Zetian's room with the body guard in the name of eradicating treacherous court officials. Wu Zetian had no choice but to abdicate directly, so Li Xian took the lead. Zhang Jianzhi also became an important changer in the fate of the Tang Dynasty.
Li Xian didn't believe Zhang Jianzhi.
After Wu Zetian abdicated, she dropped eye drops in front of Li Xian and told him that even if there was no coup, the position of the emperor would be passed on to him, hoping that he would not listen to the villain, so Li Xian doubted Zhang Jian's intention. Plus Wu Sansi framed Zhang Jian, saying that Zhang Jian impeached Wei Hou's chaotic government. Zhang Jian couldn't tell, so he dismissed from office. After returning to his hometown, he was exiled to Lingnan for offending the powerful people in the DPRK, and finally he was depressed.