The conspiracy had roots in personal insecurity rather than ideology. Zhang Miao had once been friends with both Cao Cao and Yuan Shao, but Yuan Shao wanted him dead, and Zhang Miao feared that Cao Cao would eventually sacrifice him to appease his powerful ally. Chen Gong, who had originally helped Cao Cao seize Yan Province, felt his talents were being overlooked in favor of other officers. When Chen Gong approached Zhang Miao with a plan to revolt, the ground was already prepared. They invited Lu Bu -- arguably the most feared warrior in China, a man whose personal combat prowess was the stuff of legend -- to serve as the new governor. Lu Bu arrived with his army, and province after province fell to him without a fight.

Only Juancheng, Dong'a, and Fan remained loyal to Cao Cao, and their survival owed much to a handful of quick-thinking subordinates. Xun Yu, defending Juancheng where Cao Cao's own family sheltered, saw through a deception attempt and prepared the city's defenses before sending an urgent letter to Xiahou Dun in Puyang. Xiahou Dun marched immediately, but his departure left Puyang exposed, and Lu Bu seized it. Cheng Yu rallied the defenders at Fan and Dong'a, personally commanding a cavalry force that held Chen Gong at Cangting Ford and prevented him from crossing the river. These acts of desperate loyalty preserved a foothold for Cao Cao's return.

When Cao Cao returned to fight Lu Bu, the two armies deadlocked for over a hundred days. Famine stalked both camps. At one point, Lu Bu's cavalry charged Cao Cao's Qingzhou Corps, scattering them in panic. Cao Cao galloped forward to rally his men, but a fire broke out and he fell from his horse, burning his left hand. Later, when the Tian clan in Puyang switched sides and let Cao Cao's forces into the city, the situation turned to chaos. Cao Cao set fire to the eastern gate as a signal of commitment, but came under attack and was defeated within the city walls. Lu Bu's horsemen captured him without recognizing him. Cao Cao pointed at a passing rider on a yellow horse and claimed the man was him. The horsemen released their prisoner and gave chase, and Cao Cao dashed through the burning gate to safety.

The decisive moment came in the summer of 195. Lu Bu learned that Cao Cao was camped at Shengshi with only a skeleton force -- most of his soldiers were out harvesting wheat. Outnumbered roughly ten to one, Cao Cao hid half his men behind a nearby dam and left the rest in plain view as bait. Lu Bu and Chen Gong attacked without scouting and walked into the trap. The ambush shattered their army. Cao Cao pressed the advantage relentlessly. With his generals Cao Ren and Cao Hong leading the counteroffensive, they retook Yan Province city by city. Lu Bu fled east to join Liu Bei in Xu Province, beginning a chain of alliances and betrayals that would end with his execution on Cao Cao's orders in 199.

The human cost extended far beyond the battlefield. A locust plague struck during the fighting, destroying crops across the region. Starvation drove some to cannibalism. Both armies exhausted their provisions, and the conflict ended as much from mutual depletion as from military decision. Zhang Miao's family was besieged at Yongqiu for months before Cao Cao captured the city and killed Zhang Miao's brother and his entire household. Zhang Miao himself was rejected by Yuan Shu when he pleaded for help, then murdered by his own soldiers. The plains of eastern Henan and southwestern Shandong -- visible today as an endless quilt of irrigated farmland -- were, for those terrible months, a landscape of siege, ambush, and hunger.