Qin, the First United Empire (221-206 BC)
The ruler of Qin used the theory of legalists who advocated that law should be made and should strictly executed. The ruler called himself Qinshihuang (First Emperor of Qin Dynasty's). He ordered to connect the Great Wall. He not only united China through military forces, but also unified weights and measures, introduced a standard currency, and applied a Qin writing style. In addition, he also developed the main road and canal system. He also attempted to unify thoughts in order to better control his people. His name is forever tied with the "Burning the Books and Burying the Scholars" because he ordered all books except those on medicine, agriculture and divination burnt and many prominent scholars buried alive for their different opinions.
His ruthlessness and much expensive cost on building his palace, his tomb, the road and the Wall depleted the wealth of his country. Qin Dynasty was overthrown not long after his death.
Qinshihuang left behind a form of political organization, which was to endure for some 2,000 years. The most remarkable innovation was the bureaucratic apparatus that remained in the following dynasties.

The prehistory of China The Xia Dynastry(21st-17th century BC) The Shang Dynasty(17th-11th century BC) The Zhou Dynasty(11th century BC-256BC) The Spring Autumn(770-476BC) and Warring States Period(475-221BC) The Qin Dynasty(221-206BC) The Western Han Dynasty(206BC-25AD) The Eastern Han Dynasty(25AD-220AD) The Three kingdoms Period(220-280),Jin Dynasty(265-420),Northern and Southern Dynasties(420-589) The Sui Dynasty(589-618) The Tang Dynasty(618-907) The Five Dynasties and Ten Kingdoms(907-960) The Northern Song Dynasty(960-1127) The Liao Dynasty(907-1125), Western Xia Dynasty(1038-1227) and Jin Dynasty(1115-1234) The Southern Dynasty(1127-1279) The Yuan Dynasty(1206-1368) The Ming Dynasty(1368-1644) The Qing Dynasty(1616-1911) Republic of China(1912-1949) The People's Republic of China(1949-)