|Style name||Bogui (Chinese: 伯珪; pinyin: Bóguī; Wade–Giles: Po-kui)|
Not much is known of his early life but that he studied under Lu Zhi with Liu Bei, and was appreciated by a mayor surnamed Hou who made Gongsun his son-in-law. He was deployed by He Jin to quash rebellions in the north which he did successfully. Following a misunderstanding with his lord, Liu Yu, he attacked him and won control of the surrounding area; however, contrary to popular belief, he never formally received the title of prefect. During this time his former classmate Liu Bei came to serve him and got allocated the city of Pingyuan to defend.
Two cousins now formed the power in China, Yuan Shao in the north in direct competition with Gongsun Zan and Yuan Shu. Following a disagreement between the two, Gongsun Zan formed an alliance with Yuan Shu and sent his nephew Gongsun Yue to help Yuan Shu's general Sun Jian retake Yangcheng. However, Gongsun Yue died in the campaign. Using this pretext, Gongsun Zan fought against Yuan Shao after a plan to gain Han Fu's lands went awry. However Gongsun Zan eventually lost this and committed suicide killing also his wife and sisters, and his son Gongsun Xu would also be killed in battle later.
Gongsun was commander of a cavalry force and served on the northern and eastern frontiers of the Han Dynasty, fighting against various non Han Chinese peoples. In 191, Gongsun enlisted as part of the coalition against Dong Zhuo, the warlord who had seized power in Luoyang and held the emperor hostage, but used the opportunity to enlarge his territories. In late 191, Gongsun Zan appointed Zhao Yun as a general. Zhao Yun later joined another member of the attack on Dong Zhuo, Liu Bei who also served him at one point along with his comrades Guan Yu and Zhang Fei. Gongsun Zan and Liu Bei had known each other for years having studied together in their younger days. Throughout the 190s he fought a series of battles with the warlord Yuan Shao for control of north China, starting with the Battle of Jieqiao. He was defeated by Yuan in 199 in the Battle of Yijing and committed suicide by burning the pagoda he was on.
Gongsun Zan was known as "General of Baima" and renowned for his brigade of elite cavalry from Baima, made up completely of horses of pure white ("Baima" means "white horse" in modern Standard Mandarin Chinese). It seems he hit on the tactic of using all white horses in battle when he learned the barbarians he was then fighting against considered the animals sacred and would run from them instead of fighting.
Appointments and titles held
- Imperial Charioteer (御車)
- Filial and Incorrupt (孝廉) - nominated candidate to be a Gentleman Cadet (郎)
- Chief Clerk of Liaodong (遼東長史)
- Prefect of Zhuo (涿令)
- Commandant of Cavalry (騎都尉)
- General of the Household (中郎將)
- Marquis of a Chief Village (都亭侯)
- General of Uplifting Martial Might (奮武將軍)
- General of the Vanguard (前將軍)
- Marquis of Yi (易侯)
- Inspector of You Province (幽州刺史) - self-claimed title
- Chen Shou. Records of the Three Kingdoms, Volume 8, Biography of Gongsun Zan.
- Fan Ye. Book of the Later Han, Volume 73.