Cao Ren
In 200, when the forces of Cao Cao and Yuan Shao were locked in a stalemate at the Battle of Guandu, Yuan sent Liu Bei with an army to support the rebellions against Cao Cao in Yinjiang (氵隱疆; southwest of present-day Xuchang, Henan), roughly 8.3 km south of the capital. Cao Cao became worried about such developments in the territories under his control, so he sent Cao Ren to suppress the uprisings. Cao Ren observed that the rebels dared to create trouble because they had Liu Bei's support, but the men under Liu were newly recruited and inexperienced, so it was not difficult to defeat them. Cao Ren targeted the rebel chief Liu Pi and killed him in battle, and subsequently defeated Liu Bei as well. Yuan Shao attempted to cut off Cao Cao's route to the west by sending Han Meng (韓猛) southwest. Cao Ren responded to the threat by defeating Han Meng at Jiluo Hill (雞洛山; located 50 "li" northeast of present-day Xinmi, Henan). Yuan Shao became afraid and did not dare to send out his troops. Cao Ren and Shi Huan (史渙) later led a force to attack a convoy transporting supplies to Yuan Shao's camp and destroyed the food supplies.