Yu Fan
In 219, Sun Quan's general Lü Meng planned to attack Liu Bei's territories in southern Jing Province, which were guarded by Liu Bei's general Guan Yu. He claimed that he was ill and returned to Jianye (建業; present-day Nanjing, Jiangsu) to put Guan Yu off guard. He also managed to persuade Sun Quan to release Yu Fan from confinement and let Yu Fan accompany him, because Yu Fan had medical skills and could help to treat his illness.