Zhuge Jin (174 – July or August 241), courtesy name Ziyu, was a Chinese military general and politician of the state of Eastern Wu during the Three Kingdoms period of China. Born in the late Eastern Han dynasty, Zhuge Jin started his career in the 200s as an official under the warlord Sun Quan, who later became the founding emperor of Eastern Wu in the Three Kingdoms period. In 215, he served as Sun Quan's representative in a territorial dispute over southern Jing Province between Sun Quan and his ally, Liu Bei. In 219, he joined Sun Quan's general Lü Meng in an invasion of Liu Bei's territories in Jing Province after Sun Quan broke the Sun–Liu alliance. He was subsequently appointed as a general and commandery administrator. Before the Battle of Xiaoting of 221–222, Zhuge Jin attempted to dissuade Liu Bei from going to war with Sun Quan but was unsuccessful. The battle ultimately concluded with victory for Sun Quan's side; both sides made peace later and reestablished an alliance between the Eastern Wu and Shu Han states against their rival state, Cao Wei. From 222 until his death in 241, despite being rather incompetent in military affairs, Zhuge Jin served as one of Eastern Wu's top generals and participated in some battles against Cao Wei forces.
Although Zhuge Jin was not as brilliant in statecraft and military strategy as his more famous brother Zhuge Liang, he was known throughout his life for his virtuous character. He had a reputation for conducting himself with grace and decorum, and for being thoughtful, magnanimous and tactful. In return, he gained Sun Quan's trust, and Sun Quan never questioned his loyalty towards him. Zhuge Jin was also known for helping to mediate conflicts between Sun Quan and his subjects, including Zhu Zhi and Yu Fan.
Family background Zhuge Jin's ancestral home (and probably birthplace too) was in Yangdu County (), Langya Commandery (), which is located in present-day Yinan County or Yishui County, Shandong.(諸葛瑾字子瑜，琅邪陽都人也。) Sanguozhi vol. 52. There are two other accounts of his ancestral origins in the Wu Shu () and Fengsu Tong ().
The Wu Shu recorded that his ancestral family name was actually Ge () and his ancestors were originally from Zhu County (諸縣; southwest of present-day Zhucheng, Shandong) before they settled in Yangdu County. As there was already another Ge family in Yangdu County before they came, the locals referred to the newcomers as the Zhuge – combining Zhu (County) and Ge – to distinguish them from the other Ge family. Over time, Zhuge Liang's ancestors adopted Zhuge as their family name.(吳書曰：其先葛氏，本琅邪諸縣人，後徙陽都。陽都先有姓葛者，時人謂之諸葛，因以為氏。) Wu Shu annotation in Sanguozhi vol. 52.
The Fengsu Tong recorded that his ancestor was Ge Ying (), a general who served under Chen Sheng, the rebel king who led the Dazexiang uprising against the Qin dynasty. Chen Sheng later executed Ge Ying.(葛嬰至東城，立襄彊為楚王。嬰後聞陳王已立，因殺襄彊，還報。至陳，陳王誅殺葛嬰。) Shi Ji vol. 48. During the early Western Han dynasty, Emperor Wen considered that Ge Ying was unjustly put to death, so he enfeoffed Ge Ying's grandson as the Marquis of Zhu County to honour Ge Ying. Over time, Ge Ying's descendants adopted Zhuge as their family name by combining Zhu (County) and Ge.(風俗通曰：葛嬰為陳涉將軍，有功而誅，孝文帝追錄，封其孫諸縣侯，因并氏焉。此與吳書所說不同。) Fengsu Tong annotation in Sanguozhi vol. 52.
The earliest known ancestor of Zhuge Jin who bore the family name Zhuge was Zhuge Feng (), a Western Han dynasty official who served as Colonel-Director of Retainers () under Emperor Yuan ( 48–33 BCE). Zhuge Jin's father, Zhuge Gui (), whose courtesy name was Jungong (), served as an assistant official in Taishan Commandery (泰山郡; around present-day Tai'an, Shandong) in the late Eastern Han dynasty under Emperor Ling ( 168–189 CE).(諸葛亮字孔明，琅邪陽都人也。漢司隷校尉諸葛豐後也。父珪，字君貢，漢末為太山郡丞。) Sanguozhi vol. 35.
Zhuge Jin had two younger brothers and two sisters. His brothers were Zhuge Liang and Zhuge Jun ().(亮早孤，從父玄為袁術所署豫章太守，玄將亮及亮弟均之官。) Sanguozhi vol. 35. One of their two sisters married Kuai Qi ()([蒯]欽從祖祺婦，卽諸葛孔明之大姊也。) Xiangyang Qijiu Ji vol. 2. while the other married Pang Shanmin (), a cousin of Pang Tong.(襄陽記曰： ... [龐]德公子山民，亦有令名，娶諸葛孔明小姊， ...) Xiangyang Ji annotation in Sanguozhi vol. 37.
Early life In his youth, Zhuge Jin visited Luoyang, the imperial capital, where he studied classical texts such as the Mao Commentary on the Classic of Poetry, Book of Documents, and Zuo Zhuan. When his mother died, he went home and dutifully performed filial mourning. He also treated his stepmother in a courteous and respectful manner, which earned him fame for his filial piety.(瑾少游京師，治毛詩、尚書、左氏春秋。遭母憂，居喪至孝，事繼母恭謹，甚得人子之道。) Wu Shu annotation in Sanguozhi vol. 52.
When chaos broke out throughout China towards the end of the Eastern Han dynasty, Zhuge Jin fled from home and headed south to the Jiangdong region for shelter. He travelled around the region with Bu Zhi and Yan Jun, and they earned themselves fine reputations as learned men.(吳書曰： ... 與琅邪諸葛瑾、彭城嚴畯俱游吳中，並著聲名，為當時英俊。) Wu Shu annotation in Sanguozhi vol. 52. At the time ( 200s), Sun Quan had recently succeeded his deceased elder brother, Sun Ce, as the warlord ruling over the territories in Jiangdong. Hong Zi, a brother-in-law of Sun Quan (who married an elder half-sister of Quan's) noticed and recognised Zhuge Jin's talent so he recommended Zhuge Jin to serve under Sun Quan. Sun Quan treated Zhuge Jin, Lu Su and other talents who came to join him like honoured guests. Zhuge Jin then started his career under Sun Quan as a Chief Clerk (). Later, he was reassigned to the position of a Central Major ().(漢末避亂江東。值孫策卒，孫權姊壻曲阿弘咨見而異之，薦之於權，與魯肅等並見賔待，後為權長史，轉中司馬。) Sanguozhi vol. 52.
Sun–Liu territorial dispute
Sometime between June and August 215, Sun Quan sent Zhuge Jin as his representative to visit his ally, Liu Bei, who had recently seized control of Yi Province (covering present-day Sichuan and Chongqing). Zhuge Jin's task was to ask Liu Bei to "return" the territories in southern Jing Province (covering present-day Hubei and Hunan) to Sun Quan, according to an earlier agreement that Liu Bei would only use Jing Province as a temporary base and would return them to Sun Quan once he found another base. However, Liu Bei refused and said he would return the territories after he seized Liang Province.
Sun Quan ignored Liu Bei and sent his officials to assume office in the three commanderies of Changsha (), Lingling () and Guiyang () in southern Jing Province. However, Guan Yu, Liu Bei's general in charge of defending those territories, drove Sun Quan's officials away. An enraged Sun Quan then ordered his general Lü Meng to lead 20,000 troops to seize the three commanderies by force. After a standoff between both sides and tense negotiations, Liu Bei agreed to divide southern Jing Province between his and Sun Quan's domains along the Xiang River: Liu Bei would keep Nan, Lingling and Wuling commanderies in the west, while Sun Quan would take Changsha, Jiangxia and Guiyang commanderies in the east.
The territorial dispute was resolved by mid August to early September 215. Sun Quan then sent Zhuge Jin as his representative to visit Liu Bei again. During this trip, Zhuge Jin met his second brother Zhuge Liang, who was serving as an adviser to Liu Bei. They refrained from meeting each other in private(建安二十年，權遣瑾使蜀通好劉備，與其弟亮俱公會相見，退無私面。) Sanguozhi vol. 52. to dispel any suspicions that either of them was secretly collaborating with his brother against his lord.
Role in the Wu–Shu conflict Wu invasion of Jing Province
In 219, Sun Quan broke the Sun–Liu alliance and ordered his general Lü Meng to lead troops to seize Liu Bei's territories in southern Jing Province, which were guarded by Liu Bei's general Guan Yu, who was away at the Battle of Fancheng at the time. Zhuge Jin participated in the invasion, which turned out successful. Guan Yu was eventually captured and executed by Sun Quan's forces. Lü Meng died of illness a few months after the victory. In recognition of Zhuge Jin's contributions during the campaign, Sun Quan enfeoffed him as the Marquis of Xuancheng () and appointed him as General Who Pacifies the South () to replace Lü Meng as the Administrator () of Nan Commandery (南郡; around present-day Jingzhou, Hubei), the former headquarters of Liu Bei's territories in Jing Province. Zhuge Jin was stationed at Gong'an County, one of the key counties in Nan Commandery.(後從討關羽，封宣城侯，以綏南將軍代呂蒙領南郡太守，住公安。) Sanguozhi vol. 52.
In 220, Cao Pi usurped the throne from Emperor Xian, ended the Eastern Han dynasty, and established the state of Cao Wei (or Wei) with himself as the new emperor. This event marked the end of the Eastern Han dynasty and the beginning of the Three Kingdoms period in China. Sun Quan pledged nominal allegiance to Cao Pi and became a vassal of Wei. In return, Cao Pi awarded Sun Quan the title "King of Wu" and granted him autonomous rule over the Jiangdong (or Wu) territories. A year later, Liu Bei declared himself emperor and established the state of Shu Han (or Shu) to contest Cao Pi's legitimacy.
Battle of Xiaoting
In 221, when Liu Bei started the Battle of Xiaoting against Sun Quan to retake his lost territories in southern Jing Province, Sun Quan sent Zhuge Jin as his representative to meet Liu Bei and begin peace talks.(劉備東伐吳，吳王求和， ...) Sanguozhi vol. 52. Zhuge Jin told Liu Bei:
In his annotations to Zhuge Jin's biography in the Sanguozhi, the fifth-century historian Pei Songzhi rebutted Zhuge Jin's speech to Liu Bei. From Pei Songzhi's point of view, Liu Bei had good reason(s) to go to war with Sun Quan because Sun Quan thwarted his attempts to revive the Eastern Han dynasty when he broke the Sun–Liu alliance and seized Jing Province. Pei Songzhi also noted that Liu Bei's relationship with Guan Yu was so close that it could not be described in words. He remarked that if Liu Bei and Guan Yu's relationship were to be described in words in the Sanguozhi, it would take up so much space that it becomes a waste of space.(臣松之云：以為劉后以庸蜀為關河，荊楚為維翰，關羽揚兵沔、漢，志陵上國，雖匡主定霸，功未可必，要為威聲遠震，有其經略。孫權潛包禍心，助魏除害，是為翦宗子勤王之師，行曹公移都之計，拯漢之規，於茲而止。義旗所指，宜其在孫氏矣。瑾以大義責備，荅之何患無辭；且備、羽相與，有若四體，股肱橫虧，憤痛已深，豈此奢闊之書所能迴駐哉！載之於篇，寔為辭章之費。) Pei Songzhi's annotation in Sanguozhi vol. 52.
The Battle of Xiaoting ended in late 222 with victory for Sun Quan's forces, which were led by Sun Quan's general Lu Xun. Liu Bei retreated to Baidicheng (in present-day Fengjie County, Chongqing) after his disastrous defeat and died of illness in early 223.
Battles against Wei In late 222, Sun Quan, who was previously a vassal king under the Cao Wei state, broke ties with the Wei emperor Cao Pi and declared himself the independent ruler of his Eastern Wu state. He promoted Zhuge Jin to General of the Left (), granted him acting imperial authority, and ordered him to station at Gong'an County to oversee the Wu defences in southern Jing Province. He also enfeoffed Zhuge Jin as the Marquis of Wanling ().(黃武元年，遷左將軍，督公安，假節，封宛陵侯。) Sanguozhi vol. 52.
Battle of Jiangling (223)