In 546 BC, the second year of Duke Jing's reign, the sons of Cui Zhu's two wives fought each other for the right to succeed their father as leader of the clan. The two sons of Cui's deceased first wife killed the son of Cui's second wife, Tang Jiang, from her previous marriage. Cui sought help from Qing Feng, who took the opportunity to kill Cui's sons and exterminate the Cui clan. Cui Zhu and his wife both committed suicide. As a result, Qing Feng gained full control of Qi. Qing Feng's power did not last long. Just a year later, Qing Feng had a dispute with his son Qing She. Taking advantage of the discord within the Qing clan, four other aristocratic clans of Qi: Tian, Bao, Gao, and Luan, jointly attacked the Qing clan. Qing Feng fled to the
State of Lu, which soon expelled him for fear of offending Qi, and Qing settled in the
State of Wu. After the Cui–Qing unrest, Duke Jing appointed
Yan Ying as his prime minister, and the State of Qi entered a period of relative peace and prosperity. Yan Ying died in 500 BC, the 48th year of Duke Jing's reign, and is remembered as one of the greatest statesmen and diplomats of the
Spring and Autumn period. ==Succession==