The Warring States period in Chinese history (c. 475 – 221 BC) comprises the final two and a half centuries of the Zhou dynasty (c. 1046 – 256 BC), which were characterized by frequent warfare, bureaucratic and military reforms, and struggles for greater hegemonic influence among the various autonomous feudal states of the Eastern Zhou dynasty. It followed the Spring and Autumn period and concluded with the eventual unification of China by the western state of Qin under Qin Shi Huang, who conquered all other contender states by 221 BC and found the Qin dynasty, the first imperial dynasty in East Asian history.
While scholars have identified several different dates as marking the beginning of the Warring States period, Sima Qian's choice of 475 BC, the first year of King Yuan of Zhou's reign, is the most often cited due to the paucity of preceding annals after the Qin Shi Huang's burning of books and burying of scholars. The Warring States era largely corresponds to the second half of the Eastern Zhou period, where the King of Zhou nominally ruled as the de jure Chinese sovereign but had lost all political influence and served as nothing more than a negligible figurehead. This led to the various feudal states to adopt a "might makes right" approach to inter-state affairs and outright ignore the diplomatic rules previously observed according to the Rites of Zhou, and such a decentralized political dynamic served as the backdrop for the machinations of the eponymous Warring States. The label "Warring States period" derives from the Record of the Warring States, a work of history compiled during the early Han dynasty (202 BC – 220 AD).