Jia Nanfeng (257-300) was Empress of Jin from 290 to 300, succeeding Yang Zhi and preceding Yang Xianrong. She was the wife of the developmentally disabled Emperor Sima Zhong, and she was known to be jealous, violent, and murderous, with her intrigues playing a major role in the War of the Eight Princes.
Jia Nanfeng was born in 257 AD, the daughter of Wei general Jia Chong, who would help the Sima clan come to power during the 260s AD. In 272, she married Emperor Sima Yan's developmentally disabled son Sima Zhong, the Crown Prince of Jin, and she became known as violent and murderous, jealously killing Sima Zhong's concubines when they became pregnant. She also maintained her influence at court by writing letters to her father-in-law Sima Yan while impersonating her incapable husband, reassuring Sima Yan that Sima Zhong could inherit the throne and thus ensuring that Jia Nanfeng would become Empress. When Sima Yan died in 290 AD, Empress Dowager Yang Yan's father Yang Jun was chosen as regent for Sima Zhong, but Yang Jun excluded the Sima clan from the regency and concentrated power around his own clan. Jia Nanfeng recruited Sima Wei into a conspiracy against the Yang clan, and, on 5 April 291 AD, Sima Wei led troops into the capital and had Yang Jun and his clan massacred on Jia Nanfeng's orders; they also executed Yang Jun's rival Sima Liang, who had also sought to consolidate power around himself after his rival's downfall. Jia Nanfeng then had Sima Wei betrayed by his armies and executed, fearing that he would eventually usurp the throne. With Sima Wei dead, Jia Nanfeng was nearly in complete control of the court, but she still faced the threat posed by Sima Zhong's son Sima Yu (born from a concubine). Jia Nanfeng had Sima Yu intoxicated into writing self-incriminating letters of treason and persuaded Sima Lun to have Sima Yu assassinated in 299 AD, fearing that he still posed a threat to her even after he was demoted to commoner by his father. However, a year later, Sima Lun betrayed Jia Nanfeng and accused her of forging the edict leading to Sima Yu's death, and Jia Nanfeng was deposed and forced to commit suicide by drinking wine containing gold fragments.