Unifying the empire

King Zheng of Qin conquered the last of his opponents and unified China as the First Emperor of the Qin dynasty ("Qin Shi Huang") in 221 BC. Intending to impose centralized rule and prevent the resurgence of feudal lords, he ordered the destruction of the sections of the walls that divided his empire among the former states. To position the empire against the Xiongnu people from the north.