The Tang Dynasty began to decline after the Anshi Rebellion, but there were still many Ming Emperors and Sages, and these people even almost revived the Tang Dynasty! For example, during the reign of Emperor Wuzong of Tang, Li Yan appointed Li Deyu as the prime minister, and the two of them worked together to create a situation of "Huichang Zhongxing" in just a few years. However, after Tang Wuzong's death, li Deyu, the sage minister, was attacked by Tang Xuanzong and was demoted to death.
Li Deyu was born in the Li clan of Zhao County, Hebei Province, and his ancestors served as high-ranking officials in the Tang Dynasty, such as his father Li Jifu, who was the prime minister during the Tang Xianzong period. Although Li Deyu was born into a family of officials and eunuchs, he still studied hard, but he did not like to read dead books and did not want to take the imperial examination. Because his father served as the prime minister in the imperial court, Li Deyu has been working in the local area to avoid suspicion, "accumulating the governments to engage in it."
It was not until after Tang Muzong ascended the throne that Li Deyu served in the imperial court, but due to the "Niu-Li party struggle", he was quickly expelled from the imperial court and served in Zhejiang and Sichuan successively. During Li Deyu's work in the local area, he relied on his own talents to govern the local government very well, "Deyu has experienced the town and heard of his political achievements." During the reign of Emperor Wenzong of Tang, Li Deyu briefly entered the dynasty as chancellor, but was soon released from the region.
After Emperor Wuzong of Tang ascended the throne, he was bent on reviving the Tang Dynasty, and immediately transferred Li Deyu to the imperial court and directly appointed him as prime minister. During the Huichang period, Li Deyu "used martial arts to fix the chaos and use culture to govern Huaxia", attacking the forces of the feudal towns internally and pacifying the Zelu region; externally, he also suppressed the power of eunuchs, laid off redundant officials, and reformed the government. With the support of Tang Wuzong, Li Deyu showed his talents and created the "Huichang Zhongxing".
Both the people at that time and the historians of later generations had a high evaluation of Li Deyu. For example, the poet Li Shangyin praised Li Deyu as "a good minister of all ages, a high-ranking scholar of a generation"; Hu Yin of the Song Dynasty believed that "Emperor Wuzong used Li Deyu as a phase, and the Tang Dynasty was almost better than Zhongxing". The modern thinker Liang Qichao ranked Li Deyu alongside Guan Zhong, Shang Martin, Zhuge Liang, Wang Anshi, and Zhang Juzheng, calling them the six great statesmen of China.
However, Li Deyu ultimately failed to realize the ideal of the Zhongxing Tang Dynasty, because he was killed by another Ming Jun, and that Ming Jun was Tang Xuanzong! In 846, Emperor Wuzong of Tang fell ill and died, and the eunuchs corrected the edict and proclaimed Emperor Wuzong's uncle Li Chen as emperor for Emperor Xuanzong of Tang. Tang Xuanzong was also a Ming Emperor of the late Tang Dynasty, known as "Little Taizong", but the day after he took office, he deposed Li Deyu from the post of prime minister.
At the same time, Emperor Xuanzong of Tang appointed Lee's political enemies Baek Min-jung (Paik Ju-yi's younger brother)and Choi Hyun as their counterparts, who continued to fabricate charges to retaliate against Lee Deok-yu. Li Deyu was degraded again and again, and finally demoted to Yazhou Sihu to join the army. Yazhou is now Sanya, but it was very backward at that time. After all, Li Deyu was the prime minister and had great prestige and could not be directly executed, so Tang Xuanzong adopted the method of "degrading death".
During the Tang Dynasty and Song Dynasty, many famous figures were "degraded to death", such as Kou Zhun. In 850, after a long journey to Yazhou, Li Deyu could not withstand the double blow of body and mind, and finally died in Yazhou at the age of 63. Although Tang Xuanzong was considered a Ming Emperor, none of the prime ministers he appointed during his reign could reach the level of Li Deyu, to which later generations commented, "The Xuan Dynasty had a Li Deyu and could not use it.
References: 1. Old Book of Tang; 2. New Book of Tang; 3. Quan Tang Wen; 3. "Six Statesmen of China"