Li Deyu (; 787 – January 26, 850Academia Sinica Chinese-Western Calendar Converter. Bo Yang Edition of the Zizhi Tongjian, vol. 60 .Old Book of Tang, vol. 174.), courtesy name Wenrao (), formally the Duke of Wei (), was a Chinese poet, politician, and writer during the Tang dynasty, serving as a chancellor during the reigns of brothers Emperor Wenzong and Emperor Wuzong and (briefly) their uncle Emperor Xuānzong. He was the leader of the so-called Li Faction in the decades-long Niu-Li Factional Struggles, and was particularly powerful during Emperor Wuzong's reign, dominating the court scene and guiding policies during the campaigns against the crumbling Uyghur Khanate and against the warlord Liu Zhen. After Emperor Wuzong's death, Emperor Xuānzong, who had long despised him for his hold on power, had him demoted and banished, where he died in exile.
Background Li Deyu was born in 787, during the reign of Emperor Dezong. His grandfather Li Qiyun () served as the chief imperial censor, and his father Li Jifu would eventually serve as a chancellor during the reign of Emperor Dezong's grandson Emperor Xianzong. It was said that Li Deyu was ambitious in his youth and was studious, particularly concentrating on the Book of Han and the Zuo Zhuan. However, he did not want to submit to imperial examinations. During Emperor Dezong's Zhenyuan era (785–805), when Li Jifu was in exile, Li Deyu accompanied his father and did not seek an official career.
During Emperor Xianzong's reign During the reign of Emperor Xianzong, Li Jifu became chancellor, and it was said that because Li Deyu wanted to avoid appearance of impropriety, he did not serve at the office of the imperial censors or one of the three main bureaus of the imperial government. Rather, he served on the staff of various regional governors. In 816, after the chancellor Zhang Hongjing left the chancellor post and became the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi), Zhang invited Li Deyu to serve as a secretary. In 819, when Zhang returned to the capital Chang'an to pay homage to the emperor and subsequently remained at Chang'an, Li Deyu was made an imperial censor with the title Jiancha Yushi ().
During Emperor Muzong's reign In 820, Emperor Xianzong died and was succeeded by his son Emperor Muzong.Zizhi Tongjian, vol. 241. Emperor Muzong made Li Deyu, in addition to his imperial censor position, an imperial scholar (翰林學士, Hanlin Xueshi) as well. It was said that because Emperor Muzong had long heard about Li Jifu while he was crown prince, he had respect for Li Deyu. Soon thereafter, Li Deyu was made Tuntian Yuanwailang (), a low-level official at the ministry of public works (工部, Gongbu), and continued to be imperial scholar. It was said that because Li Deyu saw that at the time, the imperial relatives were becoming influential and making improper requests, he submitted a petition that requested that imperial relatives be required to meet the chancellors at the Office of the Chancellors, rather than at private homes. Li Deyu was then promoted to be Kaogong Langzhong (), a supervisory official at the ministry of civil service affairs (吏部, Libu), and put in charge of drafting edicts.
In 821, Li Deyu was involved in an incident that was considered one of the precipitating incidents of the coming Niu-Li Factional Struggles. At that time, both Li Deyu and Yuan Zhen were involved in power struggles with Yuan's fellow Zhongshu Sheren (中書舍人, mid-level official at the legislative bureau of government (中書省, Zhongshu Sheng)) Li Zongmin, particularly since Li Deyu had long resented Li Zongmin and Niu Sengru for what appeared to be harsh criticism against Li Jifu while Li Jifu was chancellor in the third year of Yuanhe 元和 (803). Meanwhile, Li Zongmin's junior colleague at the legislative bureau, Yang Rushi () and the deputy minister of rites (禮部侍郎, Libu Shilang) Qian Hui () were in charge of overseeing the imperial examinations. The military governor Duan Wenchang (a former chancellor) and the imperial scholar Li Shen both made secret pleas to Qian for certain examinees. However, when the results were announced, the examinees that Duan and Li Shen recommended were not given passing results, while among those passing the examinations were Zheng Lang, the brother of the examination bureau (門下省, Menxia Sheng) official Zheng Tan; Pei Zhuan () the son of the military governor Pei Du (also a former chancellor); Li Zongmin's son-in-law Su Chao (); and Yang Rushi's brother Yang Yinshi (). This thus brought a popular uproar, and Duan submitted a report accusing Yang Rushi and Qian of being unfair. When Emperor Muzong requested opinions from the imperial scholars, Li Deyu, Yuan, and Li Shen all agreed with Duan's opinion. Emperor Muzong thus ordered Li Zongmin's colleague Wang Qi () to conduct a re-examination, while demoting Qian, Li Zongmin, and Yang Rushi to be prefectural prefects and deposing 10 of the examinees selected by Qian and Yang Rushi. This was said to be the start of some 30 years of struggles between Li Deyu and his associates (known as the Li Faction) and Li Zongmin and his associates (known as the Niu Faction, named after Niu).
In 822, Li Deyu was himself made a Zhongshu Sheren, and continued to serve as imperial scholar. He was considered a possible chancellor candidate, as well as Niu. In 823, Emperor Muzong made a chancellor, while Li Deyu was sent out of Chang'an to serve as the governor (觀察使, Guanchashi) of Zhexi Circuit (浙西, headquartered in modern Zhenjiang, Jiangsu). Li Deyu believed that this was the machination by then-chancellor Li Fengji to squeeze him out so that Niu could be made chancellor, and thereafter resented Niu and Li Fengji even more.Zizhi Tongjian, vol. 243.
At the time that Li Deyu was made the governor of Zhexi, Zhexi had just suffered through a plot by the officer Wang Guoqing () to overthrow Li Deyu's predecessor Dou Yizhi, and it was said that after the plot was over, Dou exhausted the circuit treasury trying to placate the soldiers. It was said that Li Deyu lived frugally, and gave the remainder of his own expense budget to the soldiers, such that while he did not give them all that much, they were satisfied, and that two years after his commission, the treasury was full again. It was also said that he sought to change the ways of the circuit's people, to eliminate customs that were harmful to them. For example, the people of the circuit were superstitious and fearful of evil spirits, such that if close family members were ill, they would abandon their family members. Li Deyu taught the knowledgeable among the people that this was undue superstition, and further punished those who abandoned family members, such that within a few years, this custom was gone. He also catalogued the various temples in the circuit—such that only those that worshipped good historical figures were allowed to remain, while he destroyed 1,010 other temples. He further destroyed 1,460 houses in the mountains so that they could not be used by bandits as operation bases.
During Emperor Jingzong's reign Emperor Muzong died in 824 and was succeeded by his son Emperor Jingzong. The young Emperor Jingzong was said to be wasteful in his living style, and later in 824 he ordered that Zhexi Circuit submit a number of silver vessels for palace use. Li Deyu petitioned that the order to set aside due to the expenses involved for the circuit. He received no response on his petition, although his subsequent petition to set aside an order for submitting silk was granted. Also in late 824, Wang Zhixing the military governor (Jiedushi) of nearby Wuning Circuit (武寧, headquartered in modern Xuzhou, Jiangsu), requested permission for him to let people take tonsure (i.e., to become Buddhist monks) at Si Prefecture (泗州, in modern Huai'an, Jiangsu), to seek divine favors for Emperor Jingzong. Emperor Jingzong initially agreed. As a result, people were rushing to Si Prefecture to take tonsure, to avoid taxes. Li Deyu submitted an objection and pointed out that if this continued, Zhexi and its Zhedong (浙東, headquartered in modern Shaoxing, Zhejiang) and Fujian (福建, headquartered in modern Fuzhou, Fujian) would lose some 600,000 battle-capable young men, Emperor Jingzong ordered a stop to the practice.
In 825, Li Deyu submitted a six-part petition urging Emperor Jingzong to change his ways entitled the Six Maxims of the Red Screen (), written in six poems with 12 four-character lines each, pointing out the emperor's inappropriate behavior in six areas and hoping that he would change:
That he was late to meetings with imperial officials and did not hold them often enough. That he was wearing inappropriate clothing. That he was requesting too many tributes. That he was taking honest counsel lightly. That he was close to scoundrels. That he was seeking for pleasures in too many places.
Emperor Jingzong issued an edict thanking and praising Li Deyu. It was said that Li Deyu hoped that this would catch Emperor Jingzong's attention and recall him to Chang'an, but Li Fengji, who was still chancellor, prevented that possibility.
During Emperor Wenzong's reign
Prior to chancellorship Around new year 827, Emperor Jingzong was assassinated and succeeded by his younger brother Emperor Wenzong. In 829, Emperor Wenzong recalled Li Deyu to Chang'an and made him deputy minister of defense (兵部侍郎, Bingbu Shilang). The senior chancellor Pei Du recommended Li Deyu to Emperor Wenzong to be chancellor, but Li Zongmin, who was then deputy minister of civil service affairs, was named chancellor over Li Deyu due to assistance of eunuchs. Thereafter, because Li Zongmin viewed Li Deyu as a threat, Li Deyu was sent out of Chang'an again to serve as the military governor of Yicheng Circuit (義成, headquartered in modern Anyang, Henan). Subsequently, under Li Zongmin's recommendation, Niu, who was the military governor of Wuchang Circuit (武昌, headquartered in modern Wuhan, Hubei) at that point, was recalled to be chancellor in 830, and it was said that Li Zongmin and Niu worked together to eject Li Deyu's allies out of Chang'an; even Pei was sent out of Chang'an to serve as the military governor of Shannan East Circuit (山南東道, headquartered in modern Xiangfan, Hubei).Zizhi Tongjian, vol. 244.
Later in 830, Li Deyu was moved from Yicheng to Xichuan Circuit (西川, headquartered in modern Chengdu, Sichuan), which had recently suffered from a Nanzhao incursion in 829 and was said to be weak in its defenses. Upon Li Deyu's arrival in Xichuan, he consulted with many old soldiers and officers of Xichuan to quickly familiarize himself with the fronts with Nanzhao and Tufan. He also sought reinforcements, pointing out that Xichuan's forces had been severely weakened. After his requests were granted, Li Deyu also trained the soldiers, built up the defenses of the border forts, and stored emergency food supplies, and it was said that the people of Xichuan, who were previously fearful of another Nanzhao invasion, were pacified.
In 831, Li Deyu sent messengers to Nanzhao to request that Nanzhao return some of the Xichuan people whom Nanzhao had seized during the 829 invasion, and Nanzhao returned 4,000 people.