Wu Yan came from a humble background and first began his career as an official in Tongjiang County. He was described as 8 chi tall and capable of fighting beasts. Wu Yan first served as a subordinate under the Grand Marshal of Wu Lu Kang. Lu Kang respected Wu Yan's talent but did not think that the other generals would agree in promoting him. Lu Kang devised a plan where he gathered the other generals together. Then, he had people to act madly and start swinging their swords. The other generals fled in fear but Wu Yan remained firm and even defended himself. Impressed with his bravery, Wu Yan was promoted by Lu Kang, and he became one of Lu's most trusted officers. In 272, the military commander of Xiling, Bu Chan, defected to Jin and Lu Kang was sent to deal with his revolt. Wu Yan was present at the battle. Wu Yan was eventually transferred to Jianping where he served as its administrator. Around the same time, the Inspector of Yi Province, Wang Jun, was tasked with constructing battleships in preparations for the conquest of Wu. Sawdust from the construction floated down to Wu's territories which caught the attention of Wu Yan. He brought the sawdust to the Wu emperor, Sun Hao, as evidence that Jin was planning an invasion, and that the northwestern border had to be reinforced. However, Sun Hao ignored his warnings and Wu Yan instead chained the Yangtze River to prevent an eastward advance through the rivers. At the end of 279, Jin initiated their conquest of Wu. The chains that Wu Yan had set caused a setback for the Jin navy's movement but they were dealt with by Wang Jun who melted the chains with rafts full of dummies soaked in oil. By 280, all of Wu's territories on the upper Yangtze River were conquered by Jin with the exception of Jianping, where Wu Yan continued to resist. Wu Yan only surrendered after Sun Hao formally capitulated in Jianye, thus ending the Three Kingdoms.
Service in Jin Dynasty
After the fall of Wu, surviving officials of Wu were sent to the Jin capital at Luoyang. Wu Yan was appointed by Emperor Wu of Jin as Administrator of Jincheng, Prefect of Dunhuang, and Administrator of Yanmen on separate occasions. He once served as the Interior Minister of Shunyang, where the Prince of Shunyang, Sima Chang, was said to be very arrogant and indulgent and had slandered many of the previous Interior Ministers before Wu Yan of crimes they had not committed. While Wu Yan was in Shunyang, he upheld the law and practiced strict punishments on criminals to the point that many feared him. Sima Chang did not dare to slander him and instead only recommended him to become a Cavaliers In Regular Attendance Without Assignment to avoid him. In 290, the Inspector of Jiaozhou and also a former Wu official, Tao Huangpassed away. Wu Yan was appointed Commander of Nanzhong and Inspector of Jiaozhou to replace Tao Huang. Tao's death sparked a rebellion in Jiuzhen Commandery led by Zhao Zhi who ousted the Grand Administrator of Jiaozhou but Wu Yan managed to quell the revolt. He spent more than twenty years in Jiaozhou, where he maintained the peace around the region. Near the end of his life, he requested to be replaced, so he was appointed as the Empress's Chamberlain before he died in office.
