Lü Buwei
In 247 BC, the 13-year-old Ying Zheng became king of Qin after the sudden death of King Zhuangxiang. However, Ying Zheng did not wield state power fully in his hands until 238 BC, after eliminating his political rivals Lü Buwei and Lao Ai. Ying formulated a plan for conquering the other six states and unifying China with help from Li Si and Wei Liao.