Warring States period ( 476 BC - 221 BC )

The Warring States period (simplified Chinese: 战国时代; traditional Chinese: 戰國時代; pinyin: Zhànguó Shídài) was an era in ancient Chinese history characterized by warfare, as well as bureaucratic and military reforms and consolidation. It followed the Spring and Autumn period and concluded with the Qin wars of conquest that saw the annexation of all other contender states, which ultimately led to the Qin state's victory in 221 BC as the first unified Chinese empire, known as the Qin dynasty. [wiki]