He is from the county of Yiwu in Zhejiang province (浙江省 義烏縣), his chosen name is Ruchen and his nickname is Yunfeng (字汝誠，號雲峰) [1] he was one of the Ming generals that fought in the Imjin War.
Wu was first noted in the campaign of general Qi Jiguang against the Wako pirates in the 40th year of Jiajing Emperor in 1561. as a minor officer who fought valiantly.
[3] Wu continued Qi Jiguang's method of training soldiers, and his men were often regarded as the most capable fighting force of the Ming dynasty, especially when they were put to the test in 1592 during the Imjin War.
In their official relieve effort, Wu and his men were the first to cross the Yalu river and acted as the Ming army's vanguard along with the young general Qian Shizhen, at Pyongyang, he led his men to attack the northern section of Pyongyang and was wounded by teppō in battle.
[5][6] He ran into an incident later in 1593 when his forces apparently attacked a group of Korean bandits who were attempting to raid their food supplies.