King Zhaoxiang of Qin
In 306 BC, the young King Zhaoxiang ascended to the throne, with his mother Queen Dowager Xuan serving as regent. Knowing Qin could not focus on eradicating Yiqu when it had the hostile eastern states to deal with, and her son's rule was still shaky due to numerous rival princes keen to capture the throne, Queen Dowager Xuan decided to use an approach of pretended conciliation. She invited the king of Yiqu to live long-term in the Ganquan Palace, and consummated a seductive liaison that produced two sons with him. This completely removed the Yiqu King's hostility towards Qin, as the beguiled king had lost all cautiousness around the Queen Dowager. At the same time, King Zhaoxiang was aggressively acting to weaken rival warring states in the east and south, and Queen Dowager Xuan was secretly planning with her son the eventual annihilation of Yiqu.
Li Mu
Getting rid of Li Mu became a necessity for Qin to conquer Zhao and unify China. Qin sent spies to the Zhao court, bribing key courtiers in order to persuade the King of Zhao that Li Mu was planning to revolt. The plan succeeded - Li Mu was arrested and soon executed on the king's orders. According to Sima Qian (chapter 102) this happened when King Qian, 'whose mother was a dancing girl', came to the throne.