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.
Yao Xing
Yao Xing was born in 366, when his father Yao Chang was a general under the Former Qin emperor Fu Jiān. (Who his mother was is open to interpretation; Yao Chang's wife, the later Empress She, was mentioned as his mother, but when Yao Xing later became emperor, he posthumously honored one of Yao Chang's concubines, Consort Sun, as empress dowager, which allows an inference that he could have been born of Consort Sun but raised by Empress She, but there is no conclusive evidence.) Not much is known about his life under Former Qin rule, other than that when he grew older, he served as an assistant to Fu Jiān's crown prince Fu Hong (苻宏).