In the Romance of the Three Kingdoms, After Cai Mao and Zhang Yun surrendered to Cao, they were made the governor of the water army of the Marquis of Zhennan because of the method of training water troops, which was deeply taboo by Zhou Yu. So Zhou Yu used a counter-plot to make Cao Cao kill the two water army commanders, and the mistaken killing of Cai Mao and Zhang Yun by Cao Cao was one of the reasons for Cao Cao's defeat in the Battle of Chibi, so that there was no general who was good at unifying the water army, and at the same time reduced the loyalty of the Jingzhou army.
So what is the fate of Cai Mao and Zhang Yun in history?
Cai Mao (蔡瑁), courtesy name Dejue, was a member of the Jingzhou clan at the end of the Eastern Han Dynasty, the son of Cai Yi, and his aunt (Cai Yi's sister) was the wife of The Tai wei Zhang Wen, and the eldest sister and the second sister were successively married to Huang Chengyan and Liu Biao as the successors. In the first year of The First Ping Dynasty, Liu Biaodai Wang Rui was the assassin of Jingzhou, when the Jiangnan Emperor was prosperous, Cai Mao assisted Liu Biao in pacifying Jingzhou, and during the period of serving Liu Biao, he successively served as the taishou of Jiangxia, Nan County, Zhangling and other counties, and Liu Biao served as his military division when he was awarded the title of General of Zhennan by the Han Dynasty.
After Liu Biao's death, he supported Liu Chun's succession to the throne, and in 208 AD, when Cao Cao waved his army into Jingzhou, he and Ku Yue jointly forced Liu Chun to surrender to Cao Cao, and then shi shi entered Cao Cao's command, successively serving as a lieutenant of Zhonglang, Sima and Changshui, and was knighted as the Marquis of Hanyangting.
Zhang Yun, the nephew of Liu Biao of Jingzhou in the late Eastern Han Dynasty, served Liu Biao and Cao Cao successively. His mother, Liu Shi, was a sister of Liu Biao, so she was allowed to have an in-law friendship with Cai Mao. He and Cai Mao were also favored by Liu Biao, and also became friendly with Liu Biao's second son Liu Biao. Liu Biao and Cai Shi wanted to take Liu Chun as their successor, while Cai Mao and Zhang Yun were his henchmen. Cao Cao's army reached Xinye, and Zhang Yun also surrendered with the state.
The historical Cai Mao died normally, and Zhang Yun's history book does not record the cause of death.
Cai Mao himself was a prince and nobleman, and he was a good friend of Cao Cao, so he worked under Cao Cao, and he always rose to a very high official position, and finally became a lieutenant of yue riding, was named "Marquis of Yangting", and finally died a normal death.