The Battle of Yan Province was a battle fought between the warlords Cao Cao and Lü Bu for control of Yan Province (covering present-day southwestern Shandong and eastern Henan) in the late Eastern Han dynasty. The battle lasted for at least one hundred days with an indecisive conclusion.

In 192, remnants of the Yellow Turban rebels from Qing Province invaded Yan Province and occupied Dongping and Rencheng. Liu Dai, Inspector of Yan Province, wanted to attack the rebels but Bao Xin, Chancellor of Jibei, advised him against it. Liu Dai ignored Bao Xin's warning, engaged the rebels in battle, and was eventually defeated and killed.

At that time, Cao Cao's advisor Chen Gong urged him to take control of Yan Province and secure it as a base for conquering other territories. Chen Gong volunteered to persuade Liu Dai's followers to join Cao Cao. Bao Xin, who was friendly towards Cao Cao, travelled to Dong Commandery (southwest of present-day Puyang, Henan) to invite Cao to be the new Inspector of Yan Province.

Cao Cao then attacked the Yellow Turban rebels at Shouzhang but failed to defeat them. After that, Cao Cao reformed his army, enforced military rules more strictly, and used incentives to encourage his men. He recognized that the rebels did not have a stable flow of supplies, as they relied on plundering to sustain themselves. Hence, Cao Cao launched surprise attacks on the rebels, prevented them from pillaging, and achieving ultimate victory and forcing the rebels to retreat north. Cao Cao pursued the rebels and defeated them again at Jibei (south of present-day Changqing District, Shandong). The rebels, numbering more than 300,000, including 100,000 civilians, surrendered to Cao Cao. Cao reorganized the surrendered troops to form the Qingzhou Corps (青州兵), while implementing the tuntian system for the people to provide for themselves and the military.

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