Seven major warring states existed during the Warring States period: Qin, Chu, Qi, Yan, Han, Zhao, and Wei. These seven powers dominated the final centuries of the Zhou dynasty, when the Zhou king retained ceremonial authority but had little practical control over the competing states.
The seven-state pattern emerged after the powerful State of Jin was divided in 403 BCE into Han, Zhao, and Wei. Alongside Qin, Chu, Qi, and Yan, these successor states fought shifting wars and formed temporary alliances. Their governments introduced military, legal, and administrative reforms to mobilize larger armies and collect more resources.
The number seven refers to the principal powers, not every state that existed. Smaller polities such as Song, Lu, Zhongshan, Ba, and Shu survived for part of the era. Qin eventually conquered the other six states: Han fell first in 230 BCE, and Qi surrendered last in 221 BCE. Qin’s victory ended the period and produced imperial unification.