The Warring States period ended in 221 BCE after the state of Qin conquered the other six kingdoms, reunited China and established the dominant order of autocracy. King Zheng of Qin proclaimed himself the First Emperor of the Qin dynasty. He enacted Qin's legalist reforms throughout China, notably the forced standardization of Chinese characters, measurements, road widths (i.e., cart axles' length), and currency. His dynasty also conquered the Yue tribes in Guangxi, Guangdong, and Vietnam. The Qin dynasty lasted only fifteen years, falling soon after the First Emperor's death, as his harsh authoritarian policies led to widespread rebellion.