In the 17th year of the Qin Dynasty, Nei Shiteng led his troops to destroy South Korea and captured King An of Han. The obtained Korean land was placed in Yingchuan County, and Han died.
The State of Zhao has been repeatedly invaded and occupied by the Qin army since the 11th year of the Qin Dynasty. After Qin destroyed Han, the State of Zhao suffered from drought and shortage of food and grass for many years. King Zhao was worried that the Qin army would take advantage of the victory and turn to attack Zhao. Immediately, Li Mu and other generals were dispatched overnight to guard the fortress pass, and discussed countermeasures with the conspirators. Later in the same year, Yan Heng's daughter Yan Xiangfan was sent to the Qin State, and she wrote a letter to show weakness in order to turn the conflict into friendship. Yan Xiangfan's appearance was like that of a fairy. King Yingzheng of Qin was so pleased that he named his daughter Mrs. Zhao. He then returned the letter to Zhao, saying, "If Zhao is willing to offer He's Bi, Qin is willing to form a permanent alliance with Zhao."