The success of the State of Qin lied on 1. The reform of Shangyang: Shang Yang became a chancellor of the state of Qin under Duke Xiao of Qin. He reformed Qin law, army, agriculture, etc, and promoted meritocracy. read more
King Zheng of Qin (Later Qin Shi Huang) built a state of Qin on top of these successes. Similar to King Zhaoxiang of Qin, he appointed many strong generals, Wang Jian and Wang Ben, and advisers, Wei Liao. read more
Ying Zheng was the first emperor of a united China, so he proclaimed himself Qin Shi Huang. Qin Shi Huang When Ying Zheng unified China, he considered his achievement surpassing the legendary "San Huang (three emperors)" and "Wu Di (five sovereigns)". read more
Qin is the first dynasty in Chinese history with centralized feudal society, and the emperor(Qin Shi Huang) all the military or tax issue are control by the central government. In that sense, Qin unify China(Before that, different vassal states even use different money system). read more