Chen Deng (), courtesy name Yuanlong, was a Chinese military general and politician who lived in the late Eastern Han dynasty of China. Born in a family of government officials in Xu Province, he started his career as a county chief at the age of 24 and later became an agriculture official under Tao Qian, the Governor of Xu Province. After Tao Qian's death in 194, Chen Deng supported Liu Bei to be the new Governor. However, in 196, he was forced to become a subordinate of the warlord Lü Bu after the latter seized control of Xu Province from Liu Bei. During this time, Chen Deng and his father Chen Gui pretended to be loyal towards Lü Bu, while secretly undermining his influence by dissuading him from allying with another warlord Yuan Shu. Chen Deng also secretly agreed to serve as a mole in Xu Province for the warlord Cao Cao, who controlled the Han central government. Chen Deng was then appointed as the Administrator of Guangling Commandery. During the Battle of Xiapi of 198–199, Chen Deng led his troops to join Cao Cao and assisted him in defeating Lü Bu. After the victory, Chen Deng was given an additional appointment as General Who Calms the Waves. During his tenure in Guangling Commandery, he gained high popularity among the people for good and benevolent governance – to the point where the people even wanted to follow him after learning that he had been reassigned to another commandery. He also resisted two invasions by the forces of Sun Ce, a warlord who controlled territories in the Jiangnan (or Jiangdong) region. He died in an unknown year at the age of 38 due to an illness caused by intestinal parasites.
Family background Chen Deng's ancestral home (and probably birthplace too) was in Huaipu County (), Xiapi Commandery (), Xu Province (), which is present-day Lianshui County, Jiangsu. He was born in a family of government officials. His granduncle, Chen Qiu (; 118 - 30 Nov 179The annals of Emperor Ling in Book of the Later Han recorded that Chen Qiu died in prison on the jia'shen day of the 10th month of the 2nd year of the Guang'he era. His biography in the same work recorded that he was 62 (by East Asian reckoning) when he died.), held high-ranking positions in the Han government during the reign of Emperor Ling. Chen Qiu's sons, Chen Yu () and Chen Cong (), served as commandery administrators, respectively. Chen Deng's father, Chen Gui, was the Chancellor () of Pei State (沛國; around present-day Pei County, Jiangsu).(陳球字伯真，下邳淮浦人也。子瑀，吴郡太守；瑀弟琮，汝阴太守；弟子珪，沛相；珪子登，廣陵太守：並知名。) Houhanshu vol. 56.
Early life and career At a young age, Chen Deng was already known for his ambition to dedicate his life to serving and helping the people. He was well-read, knowledgeable and talented in literary arts. He was well-versed in both classical and contemporary writings and could apply them well to various contexts.(先賢行狀曰： ... 少有扶世濟民之志。博覽載籍，雅有文藝，舊典文章，莫不貫綜。) Xianxian Xingzhuang annotation in Sanguozhi vol. 7.
When he was 24, he was nominated as a xiaolian (civil service candidate) by the local commandery office to serve in the government and was subsequently appointed as the Chief () of Dongyang County (東陽縣; west of present-day Jinhu County, Jiangsu). During his tenure, he helped the elderly, took care of orphaned children, and treated the county residents as if they were his family.(年二十五，舉孝廉，除東陽長，養耆育孤，視民如傷。) Xianxian Xingzhuang annotation in Sanguozhi vol. 7.
Service under Tao Qian and Liu Bei When a famine broke out in Xu Province, the provincial governor Tao Qian invited Chen Deng to serve as Colonel of Agriculture (). During this time, Chen Deng surveyed the lands, assessed their suitability for growing crops, and then implemented agricultural and irrigation works accordingly. Chen Deng's efforts helped to counter the famine and ensure that there were abundant food supplies for the people.(是時世荒民饑，州牧陶謙表登為典農校尉，乃巡土田之宜，盡鑿溉之利，秔稻豐積。) Xianxian Xingzhuang annotation in Sanguozhi vol. 7.
When Tao Qian became critically ill in 194, he told his subordinate Mi Zhu: "No one but Liu Bei can bring peace to this province." After his death, Mi Zhu invited Liu Bei to be the new Governor of Xu Province in accordance with Tao Qian's dying wish. When Liu Bei declined,(謙病篤，謂別駕麋笁曰：「非劉備不能安此州也。」謙死，笁率州人迎先主，先主未敢當。) Sanguozhi vol. 32. Chen Deng told him: When Liu Bei said Yuan Shu would be more suitable to be the Governor,(先主曰：「袁公路近在壽春，此君四世五公，海內所歸，君可以州與之。」) Sanguozhi vol. 32. Chen Deng replied: Kong Rong, the Chancellor () of Beihai State (北海國; around present-day Weifang, Shandong), also urged Liu Bei to accept the governorship. Liu Bei agreed and became the new Governor of Xu Province.(北海相孔融謂先主曰：「袁公路豈憂國忘家者邪？冢中枯骨，何足介意。今日之事，百姓與能，天與不取，悔不可追。」先主遂領徐州。) Sanguozhi vol. 32.
Chen Deng also wrote to the warlord Yuan Shao, who was based in Ji Province, to inform him that Liu Bei had become the Governor of Xu Province in accordance with the people's wishes. Yuan Shao approved and remarked that Liu Bei deserved the appointment since he had the people's support.(獻帝春秋曰：陳登等遣使詣袁紹曰：「天降灾沴，禍臻鄙州，州將殂殞，生民無主，恐懼姦雄一旦承隙，以貽盟主日昃之憂，輒共奉故平原相劉備府君以為宗主，永使百姓知有依歸。方今寇難縱橫，不遑釋甲，謹遣下吏奔告于執事。」紹荅曰：「劉玄德弘雅有信義，今徐州樂戴之，誠副所望也。」) Xiandi Chunqiu annotation in Sanguozhi vol. 32.
Service under Lü Bu In 196, the warlord Lü Bu seized control of Xu Province from Liu Bei while the latter was away at a battle against a rival warlord Yuan Shu, who controlled parts of Yang Province to the south of Xu Province. Chen Deng and his father Chen Gui were forced to become Lü Bu's subordinates. In 197, Yuan Shu proposed forming an alliance with Lü Bu, and offered to arrange a marriage between his son and Lü Bu's daughter. Chen Gui was worried that both Yuan Shu and Lü Bu would pose a greater threat to the Han central government if they became allies, so he advised Lü Bu to avoid having any ties to Yuan Shu. He also urged Lü Bu to build friendly relations with Cao Cao, the warlord who controlled the figurehead Emperor Xian and the Han central government in the imperial capital Xu (許; present-day Xuchang, Henan).(沛相陳珪恐術、布成婚，則徐、揚合從，將為國難，於是往說布曰；「曹公奉迎天子，輔讚國政，威靈命世，將征四海，將軍宜與恊同策謀，圖太山之安。今與術結婚，受天下不義之名，必有累卵之危。」) Sanguozhi vol. 7.
Lü Bu heeded Chen Gui's advice and rejected Yuan Shu's offer. He also arrested Yuan Shu's messenger, Han Yin (), and sent him as a prisoner to the imperial capital Xu, where Han Yin was publicly executed. After that, Chen Gui asked Lü Bu to send Chen Deng as his representative to meet Cao Cao, but Lü Bu refused. However, after the Han central government sent an emissary to appoint Lü Bu as General of the Left (), Lü Bu was so happy that he sent Chen Deng as his representative to Xu to thank Cao Cao and the Han imperial court.(布亦怨術初不己受也，女已在塗，追還絕婚，械送韓胤，梟首許市。珪欲使子登詣太祖，布不肯遣。會使者至，拜布左將軍。布大喜，即聽登往，并令奉章謝恩。) Sanguozhi vol. 7.
Serving as a mole in Xu Province In the imperial capital Xu, Chen Deng told Cao Cao that Lü Bu was courageous but foolhardy and untrustworthy, and advised Cao Cao to get rid of Lü Bu soon. Cao Cao replied, "Lü Bu has the heart of a rapacious wolf. It's really difficult to allow him to live long. You're probably the only person who understands his temperament."(登見太祖，因陳布勇而無計，輕於去就，宜早圖之。太祖曰：「布，狼子野心，誠難乆養，非卿莫能究其情也。」) Sanguozhi vol. 7. He then increased Chen Gui's salary by 2,000 dan of grain and appointed Chen Deng as the Administrator () of Guangling Commandery (around present-day Huai'an, Jiangsu) in Xu Province. Before Chen Deng left, Cao Cao held his hand and said, "You're now in charge of the task in the east." Chen Deng had agreed to serve as a mole in Xu Province and assist Cao Cao in eliminating Lü Bu.(奉使到許，太祖以登為廣陵太守，令陰合衆以圖呂布。) Xianxian Xingzhuang annotation in Sanguozhi vol. 7.(即增珪秩中二千石，拜登廣陵太守。臨別，太祖執登手曰：「東方之事便以相付。」令登陰合部衆以為內應。) Sanguozhi vol. 7.
When Chen Deng returned to Xu Province, an angry Lü Bu confronted him, brandished his ji at him and said, "Your father advised me to side with Cao Cao and reject Yuan Shu's offer. Now, (after following his advice,) I have gained nothing, while you and your father got promoted and rewarded. You must have tricked me! What do you have to say?"(始，布因登求徐州牧，登還，布怒，拔戟斫机曰：「卿父勸吾恊同曹公，絕婚公路；今吾所求無一獲，而卿父子並顯重，為卿所賣耳！卿為吾言，其說云何？」) Sanguozhi vol. 7. Chen Deng maintained his composure and calmly replied: Lü Bu's anger subsided.(布意乃解。) Sanguozhi vol. 7.
Governing Guangling Commandery After assuming office as the Administrator of Guangling Commandery, Chen Deng governed his jurisdiction fairly and justly and built up a good reputation. He also managed to induce Xue Zhou (), a pirate leader, to lead thousands of his followers to surrender to the local government. Within the first year of his governorship, Chen Deng's policies yielded good results in Guangling Commandery and earned him the respect and love of the commandery's residents. Chen Deng remarked, "This can be put to good use."(登在廣陵，明審賞罰，威信宣布。海賊薛州之羣萬有餘戶，束手歸命。未及期年，功化以就，百姓畏而愛之。登曰：「此可用矣。」) Xianxian Xingzhuang annotation in Sanguozhi vol. 7. He is generally credited with the establishment of the Gaojia Weir Gāojiāyàn) around the year Jian'an 5 (), a massive 30-li embankment intended to protect nearby farmland and the Han or Hangou Canal Hángōu) constructed centuries before by the hegemon Fuchai of Wu from floods of the Huai River... It forms the core of the present Hongze Embankment, still used for the same purpose. He also constructed roads through the territory.
Battle of Xiapi
In 198, Cao Cao led his forces to attack Lü Bu at Xiapi (下邳; present-day Pizhou, Jiangsu), the capital of Xu Province. Chen Deng responded by leading troops from Guangling Commandery to assist Cao Cao in attacking Lü Bu. At the time, as Chen Deng's three younger brothers were in Xiapi, Lü Bu held them hostage and threatened to kill them if Chen Deng did not make peace with him. Chen Deng refused to start peace talks with Lü Bu, and ordered his troops to press on the attack on Xiapi. During the battle, Zhang Hong (), an officer under Lü Bu, sensed that Lü Bu would eventually lose and became afraid that he would get into trouble, so he secretly freed Chen Deng's brothers at night and brought them out of Xiapi to join Chen Deng. Lü Bu eventually lost the battle against Cao Cao, and was captured and executed.(太祖到下邳，登率郡兵為軍先驅。時登諸弟在下邳城中，布乃質執登三弟，欲求和同。登執意不撓，進圍日急。布刺姦張弘，懼於後累，夜將登三弟出就登。布旣伏誅， ...) Xianxian Xingzhuang annotation in Sanguozhi vol. 7.
Resisting Sun Ce's attacks After defeating Lü Bu, Cao Cao suggested to the Han central government to grant Chen Deng an additional appointment, General Who Calms the Waves (), in addition to his existing appointment as the Administrator of Guangling Commandery. At the time, Chen Deng was highly popular among the people living in the Jianghuai region (covering parts of present-day Anhui and Jiangsu). During this time, he came up with the idea of conquering the Jiangnan (or Jiangdong) region,(登以功加拜伏波將軍，甚得江、淮間歡心，於是有吞滅江南之志。) Xianxian Xingzhuang annotation in Sanguozhi vol. 7. which at the time was under the control of the warlord Sun Ce.
Battle of Kuangqi Sometime between early 199 and the summer of 200, Sun Ce sent his forces to attack Chen Deng at Kuangqi (), a fortress in Guangling Commandery. When Chen Deng's subordinates saw that Sun Ce's invading forces outnumbered the defending troops in Guangling Commandery by more than ten times, they became fearful and worried that they could not resist the enemy. They advised Chen Deng to evacuate everyone in Kuangqi and retreat further inland away from the riverbank, and hoped that some days later Sun Ce's forces would retreat on their own, return to their boats and sail back to Jiangnan.(孫策遣軍攻登於匡琦城。賊初到，旌甲覆水，羣下咸以今賊衆十倍於郡兵，恐不能抗，可引軍避之，與其空城。水人居陸，不能乆處，必尋引去。) Xianxian Xingzhuang annotation in Sanguozhi vol. 7.