Duke Mu of Cao
Duke Mu of Cao was the eleventh ruler of the vassal State of Cao during the Chinese Eastern Zhou dynasty and Spring and Autumn period. Born Jī Wǔ, he was the son of Cáo Huìbó. In 760 BCE, Duke Mu of Cao killed his elder brother Cáo Fèibó and appointed himself ruler of the State of Cao. He was the first ruler of the State of Cao to receive the posthumous title of "Duke".