Battle of Buyur Lake

In 1388, a Ming army led by General Lan Yu undertook a military campaign against Toghus Temur, the Khan of the Mongol horde. Later that year, the Ming army found and defeated the Mongol horde at Buyur Lake, capturing many of their people.

Background
Bolstered by the successes against the Mongols in 1387, resulting in the surrender of Naghachu and his Uriyankhad horde, the Hongwu Emperor would order General Lan Yu to lead an army on a military campaign against Toghus Temur, the Khan of the Mongol horde.

Course
In December 1387, the Hongwu Emperor ordered General Lan Yu to lead a campaign against Toghus Temur. Lan Yu led a Ming army comprising 150,000 soldiers in the campaign.

General Lan Yu and his army marched through the Great Wall, to Ta-ning and then Chi'ng-chou, where they were informed by spies that Toghus Temur was encamped near Buyur Lake. Subsequently, the Ming army advanced northward across the Gobi Desert,  eventually reaching Buyur Lake.

They didn't sight the Mongol horde when they came within 40 li of Buyur Lake, disheartening General Lan Yu, but his subordinate General Wang Pi (Marquis of Tingyüan) reminded him that it would be foolish to return with such a large army without accomplishing something. The Ming army would eventually find out that the Mongol horde was located northeast of Buyur Lake, so they approached them under the cover of the darkness and a sandstorm. In 18 May 1388, near the Buyur Lake, the Ming army launched an attack against the Mongol horde, who were caught offguard by the attack. The battle concluded with the Ming capturing many of the Mongols, but Toghus Temur escaped and fled into the Mongolian steppes. However, Toghus Temur would shortly afterwards be killed by a fellow Mongol.

Aftermath
The Hongwu Emperor issued a proclamation, praising Lan Yu and comparing him to the famous General Wei Qing of the Han. Lan Yu was eventually created as the Duke of Liang with a stipend of 3,000 shih and as the Grand Tutor (T'ai-fu, which was an honorific) for his military successes. Six of Lan Yu's subordinates were created as marquises, while the other officers and soldiers received generous rewards.

Langlois (1998) stated that the Ming captured 100 family members of Toghus Temur (including Ti-pao-nu, Toghus Temur's younger son), 3000 princes and their subordinates, 77,000 men and women from the camp, various imperial seals of office, and 150,000 domesticated animals, but that Toghus Temur and his eldest son T'ien-pao-nu escaped. Dreyer (1982) stated that the Ming captured 3000 notables, 70,000 ordinary Mongols, many different domestic animals, the Mongol crown prince and his younger brother, but that Toghus Temur escaped. Tsai (2001) stated that the Ming captured Toghus Temur's second son, General Qarajang, hundreds of thousands of Mongol people, and their livestock, but that Toghus Temur and the crown prince escaped.