In the fifth year of Jian An (A.D. 198) during the Han dynasty, Cao Cao marches to the east to attack Xuzhou, with the intent to capture Liu Bei. Liu Bei is defeated and the three sworn brothers [Liu Bei, Guan Yu and Zhang Fei] lose track of each other. Cao Cao wishes to lure Liu Bei’s second brother, Guan Yu, into his service. So he follows his counsellor Cheng Yu’s plan to ‘instigate the tiger to leave the mountain’, sending Xiahou Dun to provoke Guan Yu to come out of the city to fight in open combat.
漢建安五年，曹操東征徐州，要捉拿劉備，劉備遭敗，弟兄三人失散。曹操一心想收伏劉的二弟關羽，用謀士程昱的“調虎離山”計，派夏侯惇激關羽出城來交戰。