Collection of facts about the Warring States period

This post is a collection of facts about the Warring States period (c. 475 - 221 BC). There are 8 facts listed below. Source: Wikipedia

• Preceded by the Spring and Autumn period
• During the Zhou dynasty
• Partition of Jin in 453 BC
• Han, Zhao and Wei states officially recognized by Zhou in 403 BC
• Qin's wars of unification (230 - 221 BC)
• Ended when the Qin dynasty unified China in 221 BC
• Led to first Chinese imperial dynastic state
• Record of the Warring States written about this period