Li Jingxuan

Li Jingxuan (李敬玄) (615–682), formally Duke Wenxian of Zhao (趙文憲公), was an official of the Chinese dynasty Tang Dynasty, serving as chancellor during the reign of Emperor Gaozong. He was famed for his knack of organizing the civil service system efficiently, but his downfall began in 678, when he, over his objection, was put in command of an army against Tufan and was defeated. He was removed from his post soon thereafter, and while he would return to imperial service, he would never regain the power he had.

Read more about Li Jingxuan:  Background, During Emperor Gaozong's Reign