The Warring States Period was a period of transition from slave society to feudal society in China. The culture of the various states of Xia and the cultures of Qin, Chu, Wu, and Yue exchanged and merged, and the trend of unification became increasingly strong. After the seven states of Wei, Zhao, Han, Chu, Qi, Qin, and Yan, which were carrying out feudal reforms, became strong, they launched wars of annexation, seeking to unify the middle and lower reaches of the Yellow River and the Yangtze River by force, and they constantly attacked each other.