Tumu Crisis

The Tumu Crisis (Тумугийн тулалдаан) ; also called the Crisis of Tumu Fortress  or Battle of Tumu, was a frontier conflict between the Oirat Mongols and the Chinese Ming Dynasty which led to the capture of the Zhengtong Emperor on September 1, 1449, and the defeat of an army of 500,000 men by a much smaller force. This outcome was largely due to the Chinese army's remarkably bad deployment. The Ming expedition is regarded as the greatest military debacle of the dynasty. This battle was also the very early decline in the Ming Dynasty.

In July 1449 Esen Tayisi (Chinese: 也先台吉) of the Oirat Mongols launched a large-scale, three-pronged invasion of China with his puppet khagan Toqtaq-Buqa. He personally advanced on Datong (in northern Shanxi province) in August. The eunuch official Wang Zhen, who dominated the Ming court, encouraged the 22-year-old Zhengtong Emperor to lead his own armies into battle against Esen. The size of Esen's army is unknown but a best guess puts it at some 20,000 men. The Ming army of about 500,000 was hastily assembled; its command was made up of 20 experienced generals and a large entourage of high-ranking civil officials, with Wang Zhen acting as field marshal.

On August 3 Esen's army crushed a badly supplied Chinese army at Yanghe, just inside the Great Wall. The same day the Emperor appointed his half-brother Zhu Qiyu as regent. The next day he left Beijing for Juyong Pass. The objective was a short, sharp march west to Datong via the Xuanfu garrison, a campaign into the steppe and then a return to Beijing by a southerly route through Yuzhou. Initially the march was mired by heavy rain. At Juyong Pass the civil officials and generals wanted to halt and send the emperor back to Beijing, but their opinions were overruled by Wang Zhen. On August 16, the army came upon the corpse-strewn battlefield of Yanghe. When it reached Datong on August 18, reports from garrison commanders persuaded Wang Zhen that a campaign into the steppe would be too dangerous. The "expedition" was declared to have reached a victorious conclusion and on August 20 the army set out back toward China proper.

Fearing that the restless soldiers would cause damage to his estates in Yuzhou, Wang Zhen decided to strike northeast and return by the same exposed route as they had come. The army reached Xianfu on August 27. On August 30 the Mongols attacked the rearguard east of Xianfu and wiped it out. Soon afterwards they also annihilated a powerful new rearguard of cavalry, led by the elderly Gen. Zhu Yong, at Yaoerling. On August 31 the imperial army camped at the post station of Tumu. Wang Zhen refused his ministers' suggestion to have the emperor take refuge in the walled city of Huailai, just 45 km ahead.

Esen sent an advance force to cut access to water from a river south of the Chinese camp. By the morning of September 1 they had surrounded the Chinese army. Wang Zhen rejected any offers to negotiate and ordered the confused army to move toward the river. A battle ensued between the disorganized Chinese army and the advance guard of Esen's army (Esen was not at the battle). The Chinese army basically dissolved and was almost annihilated. The Mongols captured a huge quantity of arms and armour while killing most of the Chinese troops. All the high-ranking Chinese generals and court officials were killed. According to some accounts, Wang Zhen was killed by his own officers. The Emperor was captured, and on September 3 he was sent to Esen's main camp near Xianfu.

The entire expedition had been unnecessary, ill-conceived and poorly commanded. The Mongol victory was won by an advance guard of perhaps as few as 5,000 cavalry. Esen, for his part, was not prepared for the scale of his victory or for the capture of the Ming Emperor. At first he attempted to use the captured emperor to raise a ransom and planned to conquer the undefended Ming capital of Beijing. However, his plan was foiled due to the steadfast leadership of the Ming commander in the capital, Gen. Yu Qian. The Ming leaders rejected Esen's offer, Yu stating that the country was more important than an emperor's life.

The Ming never paid a ransom for the return of the Emperor, and Esen released him four years later. Esen himself faced growing criticism for his failure to exploit his victory over the Ming and he was assassinated six years after the battle in 1455.

Although the Oirats later occupied the Ordos Desert, they never again seriously threatened the Ming state.