Duke Huan of Qi (), personal name Lü Xiaobai, was a duke of the Qi state, ruling from 685 BC to 643 BC.
Duke Huan and his long-time advisor Guan Zhong managed to transform Qi into China's most powerful polity. Duke Huan is commonly listed among the Five Hegemons of the Spring and Autumn period. Toward the end of his more than 40-year-long reign, however, Duke Huan's power began to decline as he grew ill and the Qi state came to be embroiled in factional strife. Following his death in 643 BC, Qi completely lost its predominance.
Early life and rise to power
Xiǎobái was born as one of Duke Xi of Qi's sons, though not in line of succession for the throne as he had at least two older brothers: Zhu'er and Jiu. In his youth, Xiǎobái was tutored by Bao Shuya. When Duke Xi eventually died, Zhu'er became Qi's next ruler as "Duke Xiang" but his reign was fraught with internal conflicts and scandals. Recognizing this and fearing for his pupil's life, Bao Shuya took Xiǎobái and fled with him to the state of Ju where they went on to live in exile.
Duke Xiang was assassinated in 686 BC, which allowed his cousin, Wuzhi, to ascend the throne. After just one month in office, however, Wuzhi was also murdered. With these two dead, Xiǎobái returned to Qi with the goal of becoming the next duke. He faced opposition in the form of his older brother Jiu however. Prince Jiu, by then also in exile, managed to gain the support of several high-ranking officials in Qi, his tutor Guan Zhong and Duke Zhuang of Lu. Before Jiu could be installed as new duke of Qi, however, Xiǎobái managed to seize control of Qi's government as well as its army, and was crowned as "Duke Huan of Qi" in 685 BC. The army of Lu under Duke Zhuang promptly invaded in order to install Prince Jiu on the throne, but the invading force suffered a crushing defeat at Qianshi and had to retreat. Qi's army under Bao Shuya in turn invaded Lu, and demanded Jiu and his supporters be handed over. To appease Duke Huan, Duke Zhuang then executed the rogue prince and delivered Guan Zhong to Qi as a prisoner. Guan Zhong also died in that year, depriving the ruler of Qi of his most important advisor. Having grown ill, Duke Huan was increasingly ignored by the leaders of other states, and even his authority over Qi itself declined as various political factions began to vie for power.
These factions were formed by high officials as well as six of the duke's sons. These six, namely Zhao, Wukui, Pan, Shangren, Yuan, and Yong, were all the children of different concubines, as Duke Huan's three main wives bore him no sons. As a result, all of them felt themselves entitled to the throne. Though Qi's ruler had designated Prince Zhao as his heir and even charged Duke Xiang of Song with ensuring that he would ascend the throne, this did not stop the other five from plotting their own rise to power.