Battle of Xuzhou 徐州之戰

In the 4th year of Jian'an (199), when Yuan Shu, defeated at Chen, tried to pass through Xiapi and go north to Yuan Shao, Cao Cao had Liu Bei lead Zhu Ling and others to intercept him. Cheng Yu and Guo Jia said that if Liu Bei were lent troops he would surely turn disloyal, and Cao Cao, regretting it, sent men after him, but they did not catch up. In Dong Zhao's biography too, Dong Zhao said that Liu Bei was brave and ambitious, with Guan Yu and Zhang Fei as his wings, so his true intentions could not be gauged. Yuan Shu died of illness before Liu Bei arrived. Records, Wei 1 §56Records, Shu 2 §14Records, Wei 14 §15–16 · 57

According to the Biography of the First Sovereign, Liu Bei had earlier plotted with Dong Cheng and others to kill Cao Cao, but had not acted because he was sent out on this mission. Arriving at Xiapi, Liu Bei, after Zhu Ling and the others had gone back, killed Che Zhou, the Inspector of Xu Province, had Guan Yu hold the city of Xiapi and act as its Administrator, and returned to Xiaopei himself. When Chang Ba of Donghai rebelled, many commanderies and counties turned against Cao Cao and sided with Liu Bei, and his following grew to tens of thousands; Liu Bei sent Sun Qian to ally with Yuan Shao. Liu Dai and Wang Zhong, whom Cao Cao sent, could not prevail. Records, Shu 2 §15–16Records, Shu 6 §3Records, Wei 1 §56

In the 1st month of spring in the 5th year of Jian'an (200), the plot of Dong Cheng and the others leaked and they were all executed. When Cao Cao was about to march east against Liu Bei in person, his generals said that his rival for the realm was Yuan Shao, and asked what he would do if Yuan Shao struck his rear while he left him to go east. Cao Cao said that Liu Bei was an outstanding man who would surely become a future menace if not attacked now, while Yuan Shao, though ambitious, was slow to see how things stood and would not move; Guo Jia also urged the campaign. In the Biography of Yuan Shao, Tian Feng urged a surprise attack on Cao Cao's rear, but Yuan Shao refused, pleading his son's illness. Records, Wei 1 §58Records, Wei 6 §50

Cao Cao marched east, crushed Liu Bei and captured his general Xiahou Bo. Liu Bei fled to Yuan Shao, and Cao Cao captured his wife and children. He then attacked Guan Yu, who was stationed at Xiapi, and Guan Yu surrendered; Cao Cao also attacked and defeated Chang Xi, who had sided with Liu Bei. The Biography of the First Sovereign records that Liu Bei was badly defeated and Cao Cao took in all his followers and went back with Guan Yu as well, and Guan Yu's biography records that Cao Cao made Guan Yu Lieutenant General and treated him with great courtesy. Cao Cao returned to Guandu, but Yuan Shao never came out. Records, Wei 1 §58–59Records, Shu 2 §16Records, Shu 6 §4

The fleeing Liu Bei was welcomed by Yuan Tan, the Inspector of Qing Province, and went by way of Pingyuan to Yuan Shao. Yuan Shao came out to a place 200 li from Ye to meet him, and there Liu Bei gathered his scattered soldiers again. After this fight, in the 2nd month, the Battle of Guandu began with Yuan Shao's attack on Baima. Records, Shu 2 §17Records, Wei 1 §60