Battle of Jinyang

The Battle of Jinyang (Chinese: 晉陽之戰) was fought between the elite families of the State of Jin, the house of Zhao and the house of Zhi (智), in the Spring and Autumn period of China. The other houses of Wei and Han first participated in the battle in alliance with the Zhi, but later defected to ally with Zhao to annihilate the Zhi house. This event was a catalyst to the Tripartition of Jin in 434 BC, the forming of the three states of Zhao, Wei, and Han, and the start to the Warring States period. It is the first battle described in the Song Dynasty history compendium Zizhi Tongjian.

• http://en.wikipedia.org/wiki/Battle of Jinyang