In the year 199 A.D. Cao Cao 曹操 led his army to attack Xu province after Liu Bei 劉備 seized it from Che Zhou 車冑. Liu Bei, Guan Yu 關羽 and Zhang Fei 張飛 got seperated in this battle. Guan Yu stayed back to defend to defend Xu province, where Liu Bei's spouses were, but was lured out of the city by Cao Cao's ruse. Guan Yu was heavily besieged on a small hill outside the city and Cao Cao sent Zhang Liao 張遼 to ask Guan Yu to surrender. Guan Yu agreed to surrender, but only under three conditions:
1. Liu Bei's spouses must not be harmed and well taken care of.
2. Guan Yu surrendered to the Emperor Xian and not to Cao Cao.
3. Guan Yu will go and reunite with Liu Bei as soon as he knows of his whereabouts.
Zhang Liao agreed and took Guan Yu with him to Cao Cao.