King Zhaoxiang of Qin
Reigning over 55 years, he was one of the longest-serving rulers during the Eastern Zhou Dynasty. Although making numerous policy mistakes during his later years, his aggressive territorial expansions were pivotal in consolidating the state of Qin as the dominant military powerhouse in the late Warring States period. It was the strategic dominance established during his reign that paved the way to Qin's eventual successful unification of China under his great-grandson, Ying Zheng.
King Zhuangxiang of Qin
In the meantime, through rewards and machinations, Lü Buwei helped Yiren return to Qin. He also successfully conditioned Lord Anguo's primary spouse, the childless Lady Huayang, to adopt Yiren as her own son, thereby making Yiren become Lord Anguo's legitimate heir apparent. As Lady Huayang was a native of the Chu state, she renamed Yiren to "Zichu" (lit. "son of Chu"). Upon the death of King Zhaoxiang in 251 BC, Lord Anguo ascended the throne and became historically known as "King Xiaowen", but he died in the following year just three days after his coronation. Zichu succeeded his father as the king of Qin and became historically known as "King Zhuangxiang of Qin". He named Lü Buwei as his chancellor, Lady Zhao as his queen consort, and Ying Zheng as his crown prince.