Uskhal Khan, also called the Last Emperor of Northern Yuan or the Tianyuan Emperor, born Tögüs Temür, was an emperor of the Northern Yuan dynasty based in Mongolia. He was the last powerful khan of the Mongols until the reign of Dayan Khan. Tögüs Temür was Biligtü Khan's younger brother and son of Toghon Temür, the last Yuan emperor in China. Before ascending to the Northern Yuan throne, he held the title of Prince Yi. He succeeded to the throne with the title of Uskhal Khan after Biligtü Khan died in 1378. During the funeral of the late king, the Ming court sent an embassy to participate in it and released the Mongol prince, Maidarbal, who had been captured at the battle of Yingchang in 1378. Uskhal Khan Tögüs Temür mobilized troops near Yingchang and Karakorum. He continued to press the Mingfrom the north, cooperating with Naghachu of the Jalayir in Manchuria. The Ming launched a massive attack on Mongolia in return in 1380, sacking Karakorum. The Ming army crushed the Mongol garrison under Iliyasan in North China in June 1380. Uskhal Khan's commanders, Öljei-Buqa and Nair-Buqa, invaded Lulun city, killing the Ming officer Liu Guang in the same year. The Ming dispatched a large army against the Mongols the next year. The Hongwu Emperor Zhu Yuanzhang decided to exterminate Naghachu's force in Manchuria in 1387 and two sides suffered heavier losses at a battle near Changchung city. Tögüs Temür suddenly faced a predicament in 1387 when Naghachu surrendered to the Ming due to a devastating famine. The Ming now turned their attention to the Uskhal Khan Tögüs Temür who lived in Yingchang. In 1388, he was raided by the Ming on the Buir Lake. In his escape to Karakorum, he was suddenly attacked and defeated on the Tuul River by Yesüder, a descendant of Ariq Böke, who allied with the Oirats. Yesüder's general killed the king and his son. Uskhal Khan had intended to flee westwards to join his commander Markhas. This event marked the decline of the Kublaid power and the rise of the Oirats in Mongolia.
