Passage: In July 1449 Esen Tayisi  of the Mongols launched a large-scale, three-pronged invasion of China with his puppet khagan Toqtaq-Buqa. He personally advanced on Datong  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.
Approximately how many more men did the Ming army have, over Esen's army? How many days after Esen's victory at Yanghe did the Emperor's army come across the battlefield? How many days after coming upon the battlefield of Yanghe did Wang Zhen's army decide to turn back? How many days after the Emperor left Beijing was the expedition declared victorious? How many days were between when the army came upon the Yanghe battlefield and when the expedition rached a victorious conclusion? How many is the difference in the number of people in Esen's army and the number of people in the Ming army? How many is the difference number of years the Zhentong Emperor was when he led his armies into battle and the number of generals in the Ming army? How many men did the Ming army outnumber Esen's army by? How many months Esen Tayisi of the Mongols launched a large-scale, three-pronged invasion of China until the army came upon the corpse-strewn battlefield of Yanghe? How many months after the start of his invasion of China did Esen Tayisi personally advance on Datong? How many more men was Ming's army estimated to have over Esen's army? What happened first, the army came upon the corpse-strewn battlefield of Yang or the army set out back toward China proper? When did Esen Tayisi invade China? When did the Emperor leave Beijing for Juyong Pass? When was Zhu Qiyu appointed regent? When was the Zhengtong Emperor born? Which Army did Wang Zhen fight for? Which army was being attacked first, the Mongol army or the Esens army? Which date did the Emperor leave Beijing for Juyong Pass? Which happened first, battlefield of Yanghe strewn with corpses or the army set out back towards China proper? Which was larger, Esen's army or the Ming army? Who had the largest assembled of men, the Esen army or the Ming army?