Qin's wars of unification were a series of military campaigns launched in the late 3rd century BC by the
Qin state against the other
six major states —
Han,
Zhao,
Yan,
Wei,
Chu and
Qi — within the territories that formed modern
China. By the end of the wars in 221 BC, Qin had unified most of the states and occupied some lands south of the
Yangtze River. The territories conquered by Qin served as the foundation of the
Qin dynasty.