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.
Duke Cheng of Qin
Duke Cheng was the second of the three sons of his father Duke De of Qin. His older brother Duke Xuan of Qin succeeded his father as ruler of Qin in 676 BC. But when Duke Xuan died in 664 BC, he passed the throne to Duke Cheng instead of one of his nine sons. When Duke Cheng died four years later, he did the same and passed the throne to the third brother Duke Mu of Qin, even though he had seven sons.