The Coop of TumuIn 1449 the army of Wa La tribe of Mongolian attacked the Ming dynasty. At the time, the emperor Ying Zong favoured an eunuch Wang Zhen, and accepted his wrong suggestion in leading the five-hundred thousands main forces on an expedition by himself. On the way, the army was delayed by thunderstorm, and when hearing the news of defeat in succession from the frontier, the morale of armed forces was much reduced. Again because of a series of mistakes made by Wang Zhen, the Ming army was surrounded in the Tumu fortress. The Wa La pretended to seak peace with the Ming so that they could seduce out the Ming army. They successfully captured the emperor and Wang Zhen was killed among the confused soldiers.