His personal name was Jiang Xiaobo 姜小白. He was a younger brother of Duke Xiang 齊襄公 (r. 697-686). At the end of Duke Xiang's reign the house of Qi was disturbed by succession struggles. Prince Jiu 糾 fled, with the support of Guan Zhong 管仲, to the state of Lu 魯, and Xiaobo, with the help of Bao Shu Ya 鮑叔牙, to Ju 莒.
When duke Xiang was assassinated, the two princes fought for succession. Xiaobo defeated Jiu and was received by Gao Xi 高傒 and other nobles in the capital as the new duke. Baoshu Ya was aware of Guan Zhongs abilites as advisor and suggested making him Counsellor-in-chief. Guang Zhong undertook deep-going reforms in government and military so that the state of Qi could dominate its neighbours. Besides its military power, the strength of the state of Qi made it a valubale substitute for the royal house of Zhou 周 that, after its flight to the east, had totally lost the political dominance of the Chinese states.
Qi Huangong was able to set up law and order again in the Yellow River plain and to repell the intruding "barbarian" tribes from the north and the south. In 651 duke Huan assembled the rulers of Song 宋, Lu, Wei 衛, Zheng 鄭, Xu 許, and Cao 曹, as well as an embassador of the king of Zhou, in Kuiqiu 葵丘 (modern Lankao 蘭考, Henan), where all accepted his legal dominance over the other states.
After the death of Guan Zhong, a series of other nobles took over the practical government: Shu Diao 豎刁, Yi Ya 易牙, and Kai Fang 開方. After the death of Duke Huan a succession struggle made an end to the dominant position of the state of Qi.