the time, the warlord Cao Cao, who controlled the Han court and the figurehead Emperor Xian, had recently defeated his rival Yuan Shao at the Battle of Guandu and was achieving success in his campaigns to unify northern China. In 202, Cao Cao wrote a letter to Sun Quan, demanding that Sun Quan send one of his sons to the imperial capital Xu (許; present-day Xuchang, Henan) as a hostage, so as to secure Sun Quan's allegiance towards him. Sun Quan gathered all his subjects, including Zhang Zhao and Qin Song, for a discussion, but they could not arrive at a conclusion. Sun Quan was reluctant to send one of his sons to be a hostage in the capital, so he had another discussion with only his mother Lady Wu and Zhou Yu. Zhou Yu said: Lady Wu agreed with Zhou Yu and she said: "What Gongjin said is true. Gongjin was around the same age as Bofu as he was only a month younger than Bofu. I see Gongjin as a son, so you should treat him like an elder brother." Sun Quan heeded their advice and did not send a hostage to Cao Cao. Battles against Huang Zu In 206, Zhou Yu and Sun Quan's cousin Sun Yu attacked bandits at Ma () and Bao () counties and killed their chiefs and captured thousands of enemies. Later that year, Huang Zu, the Administrator () of Jiangxia Commandery (江夏郡; around present-day Xinzhou District, Wuhan, Hubei), sent his subordinate Deng Long () to lead a few thousand troops to attack Sun Quan's forces in Chaisang Commandery (柴桑郡; around present-day Jiujiang, Jiangxi). Zhou Yu attacked Deng Long, captured him alive, and sent him as a prisoner-of-war to Wu Commandery (around present-day Suzhou, Jiangsu). In the spring of 208, Sun Quan ordered an attack on Jiangxia, which was defended by Huang Zu. Zhou Yu was assigned as the Chief Commander of the Front Army () and he, along with Lü Meng, Ling Tong and others, scored a major victory over the enemy. Huang Zu was killed by Sun Quan's forces when attempting to escape. Advising Sun Quan to go to war with Cao Cao In the late autumn of 208, Cao Cao started a campaign aimed at wiping out all opposing forces in southern China. When his forces arrived in Jing Province (covering present-day Hubei and Hunan), the provincial governor Liu Cong