ZHOU DYNASTY (1028 - 256 B.C.E)
QIN DYNASTY (221 - 210 B.C.E)
The strength of the Qin state was greatly increased by the "Legalist" reforms of Shang Yang in the fourth century BC, during the Warring States period. In the mid and late third century BC, the Qin accomplished a series of swift conquests, first ending the powerless Zhou dynasty, and eventually conquering the other six of the Seven Warring States to gain control over the whole of China. It is also the shortest dynasty in Chinese history, lasting only 15 years with two emperors.
HAN DYNASTY (221 B.C.E - 210 C.E.)
The Han dynasty was an age of economic prosperity and saw a significant growth of the money economy first established during the Zhou dynasty (c. 1050–256 BC). To pay for its military campaigns and the settlement of newly conquered frontier territories, the government nationalized the private salt and iron industries in 117 BC, but these government monopolies were repealed during the Eastern Han period. Science and technology during the Han period saw significant advances, including papermaking, the nautical steering rudder, the use of negative numbers in mathematics, the raised-relief map, the hydraulic-powered armillary sphere for astronomy, and a seismometer employing an inverted pendulum.