Li Su
On November 27, 815, at dusk, Li Su launched an attack, from his then-base of Wencheng Fence (文成柵, in modern Zhumadian), and, after dusk, after destroying the bridges between Huiqu and Cai Prefecture, and with a major winter snowstorm serving as cover, he advanced quickly to Cai Prefecture. With Li You and Li Zhongyi leading the forward attack, Li Su's forward soldiers climbed up the city walls and surprised the defending soldiers, killing them without engagements and then opening the city to allow the remainder of Li Su's soldiers to enter. Li Su's forces then attacked Wu Yuanji's fortified mansion. Wu Yuanji still commanded his own guards to defend against the attack. During the battle, Li Su, believing that Wu Yuanji's last hope would be if Dong returned quickly to save him, personally visited Dong's house and asked Dong's son Dong Chuandao (董傳道) to go to Dong Chongzhi's camp to express Li Su's good faith. Dong Chongzhi immediately abandoned his troops and returned to Cai Prefecture to surrender to Li Su. On November 29, with even the residents of Cai Prefecture joining the attack on Wu's headquarters, Wu surrendered. Li Su put him under arrest and delivered him to Chang'an.