Tumu Crisis
The Tumu Crisis (Chinese: 土木之變; pinyin: Tŭmù zhī bìan); also called Crisis of Tumubao (土木堡之變); or Battle of Tumu (土木之役), was frontier conflict between Mongolia and the Chinese Ming Dynasty leading to the capture of Zhengtong Emperor on September 8 1449 by an utterly wrong deployment. The Ming expedition is regarded as the greatest military debacle of the dynasty.
In July 1449 Esen Tayisi (也先) of the Oyirad Mongols launched a large-scale three-pronged invasion of China. He personally advanced on Datong (in northern Shanxi province) in August. The eunuch official Wang Zhen, who dominated the Ming court, encouraged the twenty-two year old Zhengtong Emperor to lead his own armies into battle against Esen. A huge army (perhaps as many as 500,000 men) was hastily assembled. Its command was made up of twenty experienced generals and a large entourage of high-ranking civil officials, with Wang Zhen acting as field marshal.
On 3 August Esen's army crushed a badly supplied Chinese army at Yanghe, just inside the Great Wall on 3 August. 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 to 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 wished to halt and send the emperor back to Beijing but their opinions were overruled by Wang Zhen. On 12 August some of the courtiers discussed assassinating Wang. On 16 August the army came upon the corpse-strewn battlefield of Yanghe. When it reached Datong on 18 August, reports from garrison commanders persuaded Wang Zhen that a campaign into the steppe would be too dangerous. The "expedition" was declared to have reached victorious conclusion and on 20 August the army set out toward Beijing.
Fearing that the restless soldiers would cause damages to his estates in Yuzhou, Wang Zhen took the decision to strike northeast and return by the same exposed route as they had come. The army reached Xianfu on 27 August. On 30 August 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 general Zhu Yong at Yaoerling. On 31 August the imperial army camped at the post station of Tumu. Wang Zhen refused 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 off access to water from a river south of the Chinese camp. By the morning of 1 September they had surrounded the Chinese army. Wang Zhen rejected any offers to negotiate and ordered the confused army to move toward the river. The Mongols attacked in force and destroyed the Chinese army, capturing large quantities of arms and armour. 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 3 September was sent to Esen's main camp near Xianfu.
The entire expedition had been unnecessary, ill-conceived, and ill-prepared. The Mongol victory was won by an advance guard of only 20,000 cavalry and the result of Chinese incompetence. Esen for his part was quite unprepared either for the scale of his victory or for the capture of the Ming emperor.
Esen at first attempted to use the captured emperor to raise a ransom.