in present-day Lu'an, Anhui). Cao Cao sent two separate forces to suppress the rebellion: Yu Jin and Zang Ba to attack Mei Cheng; Zhang Liao, with Zhang He and Niu Gai (牛蓋) as his deputies, to attack Chen Lan. Mei Cheng pretended to surrender to Yu Jin, and then led his men to join Chen Lan at Mount Tianzhu as soon as Yu Jin and Zang Ba left. The paths leading up the mountain were narrow and dangerous to travel on. When Zhang Liao wanted to attack the rebels, his subordinates advised him against it because of the hazardous terrain. However, Zhang Liao said: "This is where one-to-one fighting will take place. Only the courageous can advance forward." He then ordered his troops to make camp at the foot of the mountain. They attacked the rebels later, defeated them, and killed Chen Lan and Mei Cheng. When Cao Cao was assessing the respective contributions of his generals in the campaign, he said, "The General Who Defeats Bandits (Zhang Liao) was the one who ascended the mountain, travelled through hazardous terrain, and defeated Chen Lan and Mei Cheng." As rewards for his success, Zhang Liao was granted acting imperial authority and given additional taxable households in his marquisate. Battle of Xiaoyao Ford and aftermath When Cao Cao retreated after being defeated by Sun Quan and Liu Bei at the Battle of Red Cliffs in the winter of 208–209, he left behind Zhang Liao, Yue Jin and Li Dian with about 7,000 troops to guard Hefei from attacks by Sun Quan. Around 214, before Cao Cao went on a campaign against the warlord Zhang Lu in Hanzhong Commandery, he instructed Xue Ti (薛悌) to pass a sealed letter to the three generals at Hefei. He wrote "Open when the enemy comes" on the envelope. Later that year, Sun Quan led about 100,000 troops to attack Hefei, so they opened the letter. It read: "If Sun Quan comes, Generals Zhang and Li will go out to fight the enemy while General Yue will defend the fortress. Xue Ti will stay out of the battle." They were confused after reading the letter. Zhang Liao told Yue Jin and Li Dian: "Our lord is away on a campaign. By the time his reinforcements reach here, we are already done for. So he is actually instructing us to take advantage of the situation – when the