|General of Cao Wei|
|Style name||Wenze (simplified Chinese: 文则; traditional Chinese: 文則; pinyin: Wénzé; Wade–Giles: Wen-tse)|
|Posthumous name||Marquis Li (simplified Chinese: 历侯; traditional Chinese: 厲侯; pinyin: Lì Hóu)|
Yu Jin (died 221), style name Wenze, was a military general serving under the warlord Cao Cao in the late Eastern Han Dynasty. He joined Cao Cao in the early years of the civil wars that led to the collapse of the dynasty, and fought in many of the campaigns that established the warlord's position as a central figure in that period.
Despite having surrendered to enemy forces at the Battle of Fancheng, Yu Jin was considered by Chen Shou, the author of the historical text Records of the Three Kingdoms, to be one of the Five Elite Generals of Cao Cao, along with Zhang Liao, Xu Huang, Yue Jin, and Zhang He.
Early life 
A local of Juping (southwest of present day Tai'an, Shandong), Yu Jin first joined the military in the local government of Yan Province (兗州) to deal with the Yellow Turban Rebellion in the early 180s. When Cao Cao took over Yan Province in 193, Yu Jin became a subject of the rising warlord and was placed under the command of Wang Lang. Wang Lang was impressed by Yu Jin's talent and recommended the man to Cao Cao, who promoted him to an army commander. Yu Jin had since played active roles in campaigns against Tao Qian in Xu Province, Lü Bu in Puyang, and remnants of the Yellow Turbans around Qing Province.
Post-Battle of Wancheng 
In 197, after Cao Cao lost to Zhang Xiu at the Battle of Wancheng and retreated to Wuyin (northwest of present-day Qinyang, Henan), Yu Jin led several hundred men to hold off the pursuers, alternatively engaging the enemy and retreating to avoid a rout. As the army approached Wuyin, the enemy slowed down its pursuit, giving Yu Jin the chance to reorganise his troops and return in the most orderly manner.
Outside Wuyin, however, Yu Jin saw around a dozen men walking along the road, injured and naked. When asked, they replied that they had been robbed by the Qingzhou Corps. "Qingzhou Corps" was the name given to the former Yellow Turban rebels who surrendered to Cao Cao in Qing Province. The enraged Yu Jin led his troops to attack the die-hard bandits, who quickly ran to Cao Cao to accuse Yu Jin of treason. When Yu Jin arrived the destined campsite in Wuyin, he did not first report to his lord but instead set up camp to guard against potential pursuit from Zhang Xiu. When others reminded him that the men from the Qingzhou Corps had spoken ill of him before Cao Cao, Yu Jin shrugged it off on account that his lord possessed clear judgement. Furthermore, external enemies would prevail if defensive fortification failed to be constructed because of internal disagreements, he explained. After the entrenchment was completed, Yu Jin finally sought audience with Cao Cao and explained the situation to the latter, who was pleased and lauded the commander for his leadership quality.
Suppressing Chang Xi's rebellion 
After Cao Cao defeated his rival Yuan Shao at the Battle of Guandu in 200, Yu Jin was promoted to a deputy general for his valour at the Battle of Dushi Ford, one of the engagements in the Guandu campaign. As Yuan Shao's heirs were eradicated, Chang Xi (昌豨), a minor warlord who had previously surrendered, suddenly rebelled. Yu Jin was deployed with a force to quell the rebellion. As they were old friends, Chang Xi then submitted to Yu Jin. Many suggested that Chang Xi should be sent to Cao Cao, but Yu Jin admonished them, saying, "Don't you know the lord's order is that those who surrender after being besieged shall not be pardoned?" Personally meeting Chang Xi to say his parting words in tears, Yu Jin then had the rebel executed. When Cao Cao heard of this, he respected Yu Jin even more and promoted the latter to General of Tiger's Might (虎威將軍).
Henceforth, whenever Cao Cao personally led a campaign abroad, Yu Jin would be placed in front as the vanguard commander. When the army returned, he would be placed at the back as a rear guard. When an enemy loot was plundered, Yu Jin would reward his men handsomely, keeping nothing for himself. On the other hand, the punishment he dished out was as heavy, but just.
Battle of Fancheng 
In 219, Cao Ren was besieged by Liu Bei's general Guan Yu at Fancheng. Yu Jin, then already promoted to General of the Left (左將軍), was sent to the rescue, alongside Pang De, who had newly joined Cao Cao's force. As autumn came, a long spell of heavy rainfall flooded the Han River next to the city, drowning the majority of the relief forces. Yu Jin and Pang De climbed onto a segment of yet unsubmerged dyke and made a last stand there. As Guan Yu came round on board a large boat, Yu Jin surrendered but Pang De, refusing to give in, was captured and executed. Cao Cao heard of this and grieved for a long time, saying, "I've known Yu Jin for three decades. How could he have shown less courage than Pang De in the face of death?"
When the warlord Sun Quan defeated Guan Yu in the same year, he kept Yu Jin in his territory. During his stay in Eastern Wu, Yu Jin was treated with respect by Sun Quan, but at the same time, was serious ridiculed by Sun's straightforward official, Yu Fan, on several occasions. After the death of Cao Cao in 220, Cao Pi ended the Han Dynasty and declared himself emperor of the state of Cao Wei. Sun Quan then swore allegiance to Cao Pi, becoming a vassal king under Wei, and he returned Yu Jin to Cao Pi. By this time, however, Yu Jin was already a frail old man with a head full of white hair.
Cao Pi reinstated Yu Jin as the Borders-Pacifying General (安遠將軍) and intended to send him back to Eastern Wu as an envoy. Before he departed, Yu Jin was instructed to travel to Ye to pay his respects at Cao Cao's tomb. When Yu Jin arrived, he found that the emperor had had artists paint on the tomb, scenes of the Battle of Fancheng, in which Yu Jin was shown begging for his life to be spared and succumbing to the victorious Guan Yu, while Pang De was shown dying an honourable death. Upon seeing the mural, Yu Jin was so filled with regret that he fell ill and soon died. He was given the posthumous title of "Marquis Li" (厲侯), for people to remember him as the "stony marquis".
Yu Jin's son, Yu Gui (于圭), inherited his father's title of "Marquis of Yishou" (益壽亭侯).
See also 
- 暴慢無親曰厲。殺戮無辜曰厲。 There are two possibilities for someone to be given a posthumous title as "Li": Being Cold-blooded and arrogant, or having innocent people slaughtered. See Lost book of Zhou. Rules on assigning a posthumous name.
- Chen Shou (2002). Records of the Three Kingdoms, Volume 17, Biography of Yu Jin. Yue Lu Shu She. ISBN 7-80665-198-5.