|Advisor of Lü Bu|
|Style name||Gongtai (公臺)|
Chen Gong (died 198) was an advisor to the warlord Lü Bu during the late Han Dynasty period of Chinese history. However, he started his career under Cao Cao before defecting to Lü Bu and was executed when the latter was defeated by Cao.
In Luo Guanzhong's historical novel Romance of the Three Kingdoms, Chen Gong was given a positive makeover. He was said to have given up his official post to follow Cao Cao, who was then on the run after an attempted assassination on Dong Zhuo, a tyrannical warlord holding the emperor hostage in the imperial court. However, he left Cao Cao when he thought the latter was not an upright man either.
A local of Dong Commandery (東郡; south of present-day Shen County, Shandong), Chen Gong's year of birth is unclear. He joined Cao Cao around 190, at the time when warlords around the country formed a coalition against Dong Zhuo, a powerful warlord who held the emperor hostage. His most significant contribution while under service to Cao Cao was the taking over of Yan Province (兖州; covering present-day western Shandong) in 193 through diplomatic efforts, a strategic move which laid down the foundation for Cao Cao's subsequent rise in power.
In the next year, however, while Cao Cao was away leading a campaign against Tao Qian in Xu Province (徐州; covering present-day northern Jiangsu), Chen Gong defected to rival warlord Lü Bu along with his colleague, Zhang Miao. With the assistance of the two men, Lü Bu quickly took over most of Yan Province. Cao Cao hastily returned and laid siege on Lü Bu in Puyang (濮陽). After more than hundred days of stalemate, a famine breakout forced Lü Bu to give up his position and seek refuge under Liu Bei in Xiapi (下邳; present-day Pizhou, Jiangsu), capital of Xu Province.
In 196, Lü Bu turned on his host and took over Xiapi, proclaiming himself the regional governor and sending Liu Bei to the nearby county of Xiaopei (小沛).
In 198, Lü Bu launched an offensive against Liu Bei, who sought help from Cao Cao. Cao Cao personally led a force and laid siege on Xiapi. When Cao Cao's army reached Pengcheng (彭城; present-day Xuzhou, Jiangsu), which lies east of Xiapi, Chen Gong advised Lü Bu to grasp the initiative to strike but Lü Bu, taking the words of his wife, decided to stay put. After initial attempts to break the siege failed, Lü Bu intended to surrender but was dissuaded by Chen Gong.
The siege dragged on for two months. In the third, Cao Cao diverted the Si River and Yi River (沂水) to flood the city. Within a month, Lü Bu's subjects Hou Cheng, Song Xian and Wei Xu captured Chen Gong and defected with their troops. Lü Bu made a last stand on the city gate but was eventually overpowered and captured. When brought to Cao Cao, Chen Gong refused to return to his service and chose death so that the law could be upheld (Cao Cao maintained as a general rule that those who surrendered after being besieged were not pardoned). Cao Cao was moved and provided for Chen Gong's family henceafter.
In fiction 
Romance of the Three Kingdoms, a classic novel by Luo Guanzhong, is a romanticization of the events that occurred before and during the Three Kingdoms era. In this dramatized version of history Chen Gong was credited with much undue moral righteousness and craftiness, perhaps to accentuate the unscrupulousness of Cao Cao and incompetence of Lü Bu.
Meeting and parting with Cao Cao 
The first incident that illustrates the righteousness of Chen Gong comes in Chapter 4, where Cao Cao was fleeing from the capital Luoyang after a foiled assassination attempt on Dong Zhuo. At Zhongmu County (中牟縣), where Chen Gong was the magistrate, Cao Cao was captured. When Chen Gong interrogated the fugitive, he was so impressed with Cao Cao's loyalty to the emperor that he decided to abandon his official post and join Cao Cao, who planned to return to his home in Chenliu (陳留; around present-day Kaifeng, Henan) to raise an army against Dong Zhuo.
Along the journey, they passed by the house of Lü Boshe, a sworn brother of Cao Cao's father. There, they killed Lü Boshe's family by mistake, while Cao Cao personally murdered Lü in cold blood later. (See the article on Lü Boshe for details.) Chen Gong was shocked by what he witnessed. That night, as Cao Cao slept, Chen Gong considered killing him, but thought it unrighteous to do so. He instead left Cao Cao and travelled to his own hometown of in Dong commandery (東郡; near present-day Puyang, Henan).
Battle of Puyang 
Chen Gong's most brilliant, albeit fictitious, maneuver came during the Battle of Puyang, in which Cao Cao's force laid siege on Lü Bu in the city of Puyang (濮陽). The incident was described in Chapter 12. Chen Gong, who was then serving Lü Bu, plotted to lure Cao Cao into the city by having a local baron send a letter to Cao Cao feigning to collude with the latter. The delighted Cao Cao personally led a force deep into the city before realizing the trap. At a signal, fires were lit at all of the four city gates and Lü Bu troops cut off the evasion routes.
Separated from his men in the chaos, Cao Cao desperately sought an escape. Heading towards the north gate, he ran face-to-face into Lü Bu. Using a hand to cover his face, Cao Cao spurred his horse onward and past the enemy but Lü Bu spun around and caught up with him. Not able to recognize the warlord, Lü Bu knocked on Cao Cao's helmet with his halberd and asked, "Where is Cao Cao?" Cao Cao pointed behind and said, "The one on the dun is him." Lü Bu then gave up his true target.
As Cao Cao galloped to the city gate his horse was hit by a falling beam on fire. While trying to push the beam off, Cao Cao scalded his arms and burnt much of his hair. However, he finally managed to escape with his life under the escort of Xiahou Yuan and Dian Wei. Much later in Chapter 60 of the story, when Zhang Song, an emissary from Liu Zhang, mocked the failures of Cao Cao, the Battle of Puyang was cited among other classic battles including the Battle of Wancheng and Battle of Red Cliffs.
See also 
- Chen Shou (2002). Records of Three Kingdoms. Yue Lu Shu She. ISBN 7-80665-198-5.
- Luo Guanzhong (1986). Romance of the Three Kingdoms. Yue Lu Shu She. ISBN 7-80520-013-0.
- Lo Kuan-chung; tr. C.H. Brewitt-Taylor (2002). Romance of the Three Kingdoms. Tuttle Publishing. ISBN 0-8048-3467-9.