Li Su (Chinese: 李愬; 773–821), courtesy name Yuanzhi (元直), posthumous name Duke Wu of Liang (涼武公), was a Chinese military general and politician of the Tang dynasty. He was most well-known for his surprise attack on Cai Prefecture (蔡州; in modern-day Zhumadian, Henan), then held by the warlord Wu Yuanji, successfully capturing Wu.
Contents
Background
Li Su was born in 773, during the reign of Emperor Daizong. His father was Li Sheng, who would later rise to prominence as a major general during the reign of Emperor Daizong's son Emperor Dezong. When Li Su was young, on account of his father's accomplishments, he was first made Xielü Lang (協律郎), a low-level official in charge of music at the ministry of worship (太常寺, Taichang Si), and later the deputy minister of army supplies (衛尉少卿, Weiwei Shaoqing). His birth mother died early, so he was raised by another concubine of Li Sheng's, Lady Wang, who was created the Lady of Jin. When Lady Wang died, Li Sheng, because she was not his wife, did not have Li Su observe the mourning rites for a mother, but Li Su tearfully requested to be allowed to observe those rituals, and Li Sheng agreed.
After Li Sheng died in 793, Li Su and his brother Li Xian (李憲) built a tent next to Li Sheng's tomb, intending to observe the mourning period there. Emperor Dezong, believing the conditions were too harsh, ordered them to return to their own mansion, but after they went home for one night, the next day they were at the tomb again, and Emperor Dezong allowed them to continue to observe the mourning period there. After the mourning period was over, Li Su was made a member of the staff of Li Song the Crown Prince. He later served successively as the prefect of Fang (坊州, in modern Yan'an, Shaanxi) and then Jin (晉州, in modern Linfen, Shanxi) Prefectures, and was given the honorary title Jinzi Guanglu Daifu (金紫光祿大夫) on account of his virtues. He later was recalled to again serve on the Crown Prince's staff, and later served as the head of the Crown Prince's household.
During Emperor Xianzong's reign
During the campaign against Wu Yuanji
It was said that Li Su was full of strategies and capable in horsemanship and archery. In 816, during the reign of Emperor Dezong's grandson Emperor Xianzong, imperial troops were conducting a campaign against the warlord Wu Yuanji, who controlled Zhangyi Circuit (彰義, headquartered in modern Zhumadian, Henan)) without imperial approval, two successive imperial generals put in command of nearby Tangsuideng Circuit (唐隨鄧, headquartered in modern Zhumadian) — Gao Xiayu (高霞寓) and Yuan Zi — had suffered defeats by Zhangyi troops. Li Su volunteered to serve in the campaign, and the chancellor Li Fengji also knew of Li Su's abilities, and therefore recommended him. Emperor Xianzong thus made Li Su the military governor (Jiedushi) of Tangsuideng Circuit, as well as the prefect of its capital Tang Prefecture (唐州), replacing Yuan.
When Li Su reached the front in spring 817, it was said that the Tangsuideng soldiers, having suffered many defeats, were fearful of war. Li Su first comforted them by stating that his intentions were not to engage in battles immediately, and further personally attended to the wounded, to try to raise the morale. He also acted as if he was not taking military discipline seriously and not taking precautions toward Zhangyi troops, in order to get Zhangyi's guards down toward him. With Li Su not being well-known and the Zhangyi troops having just defeated Gao and Yuan, Zhangyi did not take particular precautions toward Li Su.
Li Su, meanwhile, requested and received reinforcements from several circuits. He then began to carry out military actions in which he targeted Zhangyi officers, captured them, and then treated them well and incorporated them into his command structure, using their familiarity with Zhangyi's defenses against Zhangyi. Such Zhangyi officers he thus captured included Ding Shiliang (丁士良), Chen Guangqia (陳光洽), Wu Xiulin (吳秀琳), Li Xian (李憲, whose name Li Su changed to Li Zhongyi (李忠義)), and Li You. His soldiers were particularly displeased at his endearment of Li You, pointing out that Li You had killed many imperial soldiers, and further accused Li You of being an agent of Wu. Li Su, in order to calm the soldiers, delivered Li You to Chang'an, ostensibly for Emperor Xianzong to execute him — and instead sent a secret petition to Emperor Xianzong, stating that he could not succeed if Li You were executed. Emperor Xianzong thereafter pardoned Li You and delivered him back to Li Su. Li Su further abolished the former orders that those who took in Zhangyi spies would be executed — instead ordering his people that if Zhangyi spies arrived, they were to be treated with kindness. As a result, the Zhangyi spies were turned toward Li Su and informed him about the status of Zhangyi troops.
After the campaign against Wu Yuanji
In the aftermaths of the campaign, Li Su's Tangsuideng Circuit was merged back into the circuit that it was split from — Shannan East Circuit (山南東道, headquartered in modern Xiangfan, Hubei) — and he was made the military governor of Shannan East. He was also created the Duke of Liang. At his urging, Emperor Xianzong, who had initially wanted to execute Dong Chongzhi, spared Dong but still exiled Dong to Chun Prefecture (春州, in modern Yangjiang, Guangdong) to serve as its census officer. When Li Su subsequently submitted a list of 150 officers who contributed to the victory, requesting that Emperor Xianzong promote them, Emperor Xianzong was displeased by the lengthy list, stating to Pei, "While Li Su accomplished an uncommonly great achievement, he recommended too many people. Based on this, then, imagine how many people Li Sheng and Hun Jian could have recommended!" Emperor Xianzong thus did not act on Li Su's recommendations.
Soon thereafter, with Emperor Xianzong considering a campaign on the western border against Tufan, in summer 818, he made Li Su the military governor of Fengxiang (鳳翔, headquartered in modern Baoji, Shaanxi) and Longyou (隴右, then also headquartered in modern Baoji) Circuits. Before Li Su could head to Fengxiang, however, Wu Yuanji's ally Li Shidao the military governor of Pinglu Circuit (平盧, headquartered in modern Tai'an, Shandong), who had, in fear after Wu's defeat, initially offered to surrender three of Pinglu's 12 prectures to imperial control, reneged on his offer. Emperor Xianzong, in anger, announced a campaign against Pinglu. Li Su was thereafter swapped in his posting with his brother Li Yuan (李愿) the military governor of Wuning Circuit (武寧, headquartered in modern Xuzhou, Jiangsu), which bordered Pinglu to the south, as well as the prefect of Wuning's capital Xu Prefecture (徐州). Once Li Su got to Xu Prefecture, he reorganized the troops into greater efficiency. At Li Su's request, Emperor Xianzong pardoned Dong and recalled him, and Li Su subsequently made Dong a commander in his army. Li Su subsequently engaged in 11 battles with Pinglu forces, prevailing each time. Around the new year 819, he captured the key Pinglu city of Jinxiang (金鄉, in modern Jining, Shandong), and thereafter continued to capture Pinglu cities. Li Shidao was thereafter killed by his own subordinate Liu Wu, who submitted to imperial authority.
While Li Su was still at Wuning, one of his subordinates recommended the physician Zheng Zhu to him, as he was often ill. Li Su's conditions improved after taking Zheng's medication, and he became closely associated with Zheng, such that Zheng became powerful over his staff members and were often interfering with governance. When the eunuch monitor Wang Shoucheng found the situation to be inappropriate and asked Li Su to remove Zheng from his staff, Li Su told him, "While Zheng Zhu is frivolous, he is talented. You should try to meet with him. If you really find him to be useless, I will remove him." Wang initially did not want to meet Zheng, but eventually agreed. After he did so, he was also pleased by Zheng's amusing speech, and therefore also became closely associated with Zheng. Zheng, not wanting others to know about how he first became associated with Li Su and Wang, subsequently falsely accused the officer who had initially recommended him, and Li Su executed the officer.
During Emperor Muzong's reign
In spring 820, Emperor Xianzong died and was succeeded by his son Emperor Muzong. Soon thereafter, Li Su was given the honorary chancellor title of Tong Zhongshu Menxia Pingzhangshi (同中書門下平章事). Further, in anticipation of potential further actions against two other circuits governed de facto independently — Chengde (成德, headquartered in modern Shijiazhuang, Hebei) and Lulong (盧龍, headquartered in modern Beijing) — Emperor Muzong made Li Su the military governor of Zhaoyi Circuit (昭義, headquartered in modern Changzhi, Shanxi). Later that year, when Wang Chengzong the military governor of Chengde died, his brother Wang Chengyuan offered to return control of the circuit to the imperial government. Emperor Muzong, in response, moved Tian Hongzheng the military governor of Weibo Circuit (魏博, headquartered in modern Handan, Hebei) — itself having previously been semi-independent from imperial rule but which had submitted to imperial command during Tian Hongzheng's governance — to Chengde, Wang Chengyuan to Yicheng, Liu Wu from Yicheng to Zhaoyi, Li Su from Zhaoyi to Weibo, and Tian Hongzheng's son Tian Bu to Heyang Circuit (河陽, headquartered in modern Jiaozuo, Henan).
The Chengde soldiers, however, had long resented Tian Hongzheng, as during Emperor Xianzong's reign Chengde and Weibo forces had often battled each other. Initially, with Weibo soldiers accompanying Tian Hongzheng to Chengde and protecting him, they did not act, but as soon as Weibo soldiers returned to Weibo in summer 821, the Chengde officer Wang Tingcou rose in mutiny and killed Tian Hongzheng. Upon hearing of Tian Hongzheng's death, Li Su changed into mourning clothes, and he stated to his soldiers:
The reason why the people of Wei Prefecture [(魏州, Weibo's capital)] were able to receive imperial culture and have peace and happiness was Lord Tian. Now, the unlawful people of Zhen Prefecture [(鎮州, Chengde's capital)] dared to murder him because they take us lightly and think that there is no one from Wei who can avenge him. You, gentlemen, have received great grace from Lord Tian. How are you going to repay him?
The soldiers all wept in sadness. Meanwhile, Niu Yuanyi (牛元翼) the prefect of Shen Prefecture (深州, in modern Hengshui, Hebei), was not willing to follow Wang. Li Su, hearing this, sent his sword and jade belt to Niu, sending a message to him: "My father had used this sword to accomplish great things. I have also used this sword to capture Cai Prefecture. Now I give it to you, Lord, and you should use it to destroy Wang Tingcou." Niu was touched, and showed the sword and belt to his soldiers and stated, "I am willing to die for the empire." Li Su was then preparing an attack against Wang in conjunction with Niu, but suddenly fell ill again. Emperor Muzong thus made Tian Bu the military governor of Weibo to succeed him. Li Su was given the title of advisor to the Crown Prince, and allowed to return to the eastern capital Luoyang to try to recover from illness. However, he died there in winter 821. He was buried with great honors.
Notes and references
Old Book of Tang, vol. 133.
New Book of Tang, vol. 154.
Zizhi Tongjian, vols. 239, 240, 241, 242, 243.