The Warring States Period, also known as the Era of Warring States, covers the period from some time in the 5th century BEC to the unification of China by the Qin Dynasty in 221 BCE.

It is nominally considered to be the second part of the Eastern Zhou Dynasty, following the Spring and Autumn Period, although the Zhou dynasty itself ends in 256 BCE, 35 years earlier than the end of the Warring States period.

As with the Spring and Autumn Period, the king of Zhou acts merely as a figurehead.

The name Warring States Period is derived from the Record of the Warring States, a work compiled early in the Han Dynasty.The date for the beginning of the Warring States Period is somewhat in dispute.

While it is frequently cited as 475 BCE (following the Spring and Autumn Period), 403 BCE — the date of the tripartition of the Jin — is also sometimes considered as the beginning of the period.The Warring States Period, in contrast to the Spring and Autumn Period, is a period when regional warlords annex smaller states around them and consolidate their rule.

The process had begun in the Spring and Autumn Period, and by the 3rd century BCE, seven major states have risen to prominence.

These Seven Warring States are the Qi, the Chu, the Yan, the Han, the Zhao, the Wei, and the Qin.

Another sign of this shift in power is a change in title: warlords still consider themselves dukes of the Zhou dynasty king; but now the warlords begin to call themselves kings, meaning they are equal to the Zhou king.