Qin Unification of China

Qin conquered the other six Warring States and unified China for the first time. The First Emperor standardised script, coinage and measures.

Qin, on the western edge of the Warring States, grew rich and strong in the 4th century BC under Duke Xiao through the Legalist reforms of Shang Yang. Ranks were granted for merit in war and counties were placed under the ruler’s direct control, and Qin’s military power grew rapidly.

Beginning with Han in 230 BC, King Zheng destroyed Zhao, Wei, Chu, Yan and Qi in turn and unified the realm in 221 BC. He invented the title "emperor" (huangdi), higher than king, and called himself the First Emperor. He extended the commandery-county system to the whole country, ruling through officials sent from the centre, and standardised the script (small seal), coinage (the banliang coin), weights and measures and axle widths. He controlled thought by burning books and burying scholars, and linked up the Great Wall against the Xiongnu.

Heavy taxes, vast building projects and harsh laws bred resentment, and the year after the First Emperor died the revolt of Chen Sheng and Wu Guang broke out. Qin fell in 206 BC and Han succeeded it. In the turmoil around the Qin–Han transition many refugees moved into Gojoseon, Wiman among them.

Qin lasted only fifteen years, but the centralised imperial system it created remained the basic framework of Chinese dynasties for two thousand years.