Guan Zhong vs Zhang Yi

As prime minister of Qi, Guan Zhong implemented state monopolies on salt and iron, standardized currency, and established a system of taxation based on land quality. These reforms made Qi the wealthiest state in China and funded Duke Huan's hegemony.

Guan Zhong organized a meeting of feudal lords at Juancheng where Duke Huan of Qi was recognized as the first official hegemon (ba) of the Spring and Autumn period. This established the hegemonic system that maintained order among the states.

Guan Zhong led Qi forces to repel the Di (Xianyun) nomads who were raiding the northern states of Xing and Wey. The campaign restored order and demonstrated Qi's role as protector of the Chinese states against barbarian incursions.

Zhang Yi served as a strategist for the state of Qin, promoting the 'horizontal alliance' (lianheng) policy. This strategy involved Qin allying with distant states to attack nearby ones, weakening the other Warring States and facilitating Qin's expansion.

Zhang Yi was appointed as chancellor (xiang) of Qin, a position he used to implement his diplomatic strategies. His tenure strengthened Qin's position among the Warring States through a combination of alliances and military pressure.

Zhang Yi promised King Huai of Chu 600 li of land in exchange for breaking the alliance with Qi. After Chu complied, Zhang Yi claimed he had only promised 6 li, causing Chu to attack Qin and suffer a major defeat at Danyang.