Query: When did Dou Wu die?
Context: Palace eunuchs imprisoned the official Li Ying (李膺) and his associates from the Imperial University on a dubious charge of treason. In 167 AD, the Grand Commandant Dou Wu (d. 168 AD) convinced his son-in-law, Emperor Huan, to release them. However the emperor permanently barred Li Ying and his associates from serving in office, marking the beginning of the Partisan Prohibitions.