Barbarians") posed to the Zhou states, and he would launch numerous campaigns to fend off these "barbarians". Most notably, he saved the states of Yan, Xing and Wey from invasions by non-Zhou groups, and tried to stop the expansion of Chu in the south. In 656 BC he led an alliance of eight states against a satellite state of Chu, Cai, and defeated it. The alliance then proceeded to invade Chu itself, and eventually a pact was concluded. Chu stopped its northward expansion and agreed to take part in an compulsory interstate meeting at Shaoling. This meeting, the first of its kind, set a precedent. Over the following years, Duke Huan convened numerous interstate meetings under the auspices of the Zhou royal family. Points of discussion during these meetings ranged from military matters to economics to general orders concerning governance and laws. Overall, the ruler of Qi managed to restore some stability in the volatile and fractious Zhou realm. Historian Cho-yun Hsu summarizes that Duke Huan "used his Ba [hegemon] leadership to set up a new order for an interstate community that was to be guarded by consensus rather than authority." Decline in power and death After almost forty years on the throne, however, Duke Huan's dominance began to gradually decline. His efforts to completely stop Chu's expansion failed, as the southern state had simply shifted its attention from the north to the east. There, along the Huai River, Chu conquered or invaded several states allied with Qi. The last major anti-Chu military alliance assembled by Duke Huan failed to stop this development, and was even defeated during the Battle of Loulin in 645 BC. 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