يوان شاو
When Cao Cao returned to Guandu after his victory over Liu Bei, who sought refuge under Yuan Shao afterwards, Yuan Shao decided to renew the campaign against Cao Cao. The aide-de-camp () Tian Feng, who had urged Yuan Shao to attack Cao Cao while he was away, advised against such a campaign, reasoning that they had lost their chance and must wait. Yuan Shao ignored Tian Feng's repeated remonstrations and imprisoned him under charges of demoralizing the army.