Guan Zhong (c. 720-645 BC) was a chancellor and reformer of the State of Qi during the Spring and Autumn Period of Chinese history. His given name was Yíwú (夷吾). Zhong was his courtesy name. Recommended by Bao Shuya, he was appointed Prime Minister by Duke Huan of Qi in 685 BC. Through Guan Zhong's reforms and skilful diplomacy Qi became the most powerful of the feudal states and Duke Huan lord protector over the feudal lords. Though knowledge of his reforms is limited, in particular he instituted a famous fiscal policy known as "balancing the light and the heavy", associated with salt and iron monopolies. Though otherwise a diverse work, the Guanzi compilation making use of his name makes similar such recommendations.