After the Mongol Yuan was defeated by Zhu Yuanzhang, its remnants retreated to the north of the desert, and the Mongols were divided into Eastern Mongolia and Western Mongolia, and there were often wars between the two tribes. In order to completely wipe out the Mongols, Ming Chengzu Zhu Di sent emissaries to make peace with the Tatar and Valar tribes, and the Wara chief Mahamu wanted to use the power of Daming to suppress the Tatars, so he submitted to the Ming Dynasty. After being suppressed by various forces, the Tatars have gradually disintegrated. At this time, the Walla had slowly become stronger, and in 1439, under the leadership of the chief of the Wallachian clan, Ye Xian, its power was constantly expanding, and its ambitions were becoming more and more inflated, and it began to look at the Ming Dynasty.
In February 1449, he also sent emissaries to pay tribute to the Ming Dynasty, but he was not satisfied with the rewards of the Ming Dynasty, so he used this as an excuse to openly challenge the Ming Dynasty, and in July 1449, he also led his army to invade the Ming border in five ways, and he personally led 30,000 elite troops to attack Datong, Shanxi. The battle report of the attack on Datong was urgently sent to Beijing, and at this time, Emperor Mingyingzong Zhu Qizhen was young and vigorous, and had the heart to make meritorious achievements, but he had no military command talent. At this time, the ministers of the imperial court were divided into two factions, one faction led by Yu Qian and others strongly opposed the emperor's imperial conquest, and the other faction was led by the grand eunuch Wang Zhen. In the end, Emperor Mingyingzong, despite the opposition of most of his ministers, decided to adopt Wang Zhen's advice and personally march. In July 1449, Zhu Qizhen let his younger brother Zhu Qiyu defend the capital, and he himself led an army of more than 500,000 to the front to support.
In August of the same year, the army led by Zhu Qizhen arrived at the front. Because Zhu Qizhen had no experience in marching and fighting, coupled with the eagerness to make meritorious contributions and despise the enemy's strength, the Ming army also had the first trick of luring the enemy to go deeper, and also ordered the army to retreat, at this time, Zhu Qizhen saw the enemy retreating, so the light enemy ventured into the swing army to chase, when the news of the defeat of the vanguard troops came, Zhu Qizhen hurriedly ordered the withdrawal of the army, so that the Ming army was physically weak, and the Wallachian army saw this opportunity and chased the Ming army all the way to Tumu Fort.
The Wallachian army besieged all the Ming legions and regiments to Tumu Fort, the Ming soldiers were sleepy and lacking, there was no food and water supply, but at this time the Ming army was still defending according to danger, and it was impossible to break through their defense line for a while, so they used the trick to lead the Ming army to the river, and the soldiers who had not drunk water for a long time rushed to quench their thirst, and also took this opportunity to lead the army to rush to kill, killing the ming soldiers who were already chaotic, many soldiers threw away their armor, and a large number of civilian generals who followed Ming Yingzong were killed, just like this, Zhu Qizhen and his men were all captured.
As for who caused the defeat of the Tumu Fort, many people believed that it was caused by the great eunuch Wang Zhen, who thought that Wang Zhen instigated Ming Yingzong's imperial conquest from the very beginning in order to show his prestige, and in the process of marching, it was also he who arbitrarily issued many wrong instructions, thus affecting Zhu Qizhen's decision-making, however, Wang Zhen was at best an inner palace eunuch, even if he was favored by the emperor, it was impossible to grasp the military and political power, let alone decide the direction of the war. Moreover, in such a life-and-death war, he would not have particularly great power. If Zhu Qizhen himself did not want to drive the imperial conquest, even if Wang Zhen instigated it, he could not make a decision for the emperor, so the most critical person who led to this defeat should be Zhu Qizhen of Ming Yingzong, because Zhu Qizhen was the supreme decision-maker, and Wang Zhen played a role as a catalyst at best, and it was also in line with the emperor's thoughts. Zhu Qizhen had no actual combat experience, and wanted to achieve the same great feats as Taizu and Emperor Chengzu, but he did not have the courage and talent of them, so he eventually ventured deep into the enemy, resulting in the total annihilation of the army.