The Mongols retreated to Karakorum after the fall of Yingchang in 1370, where they maintained the official dynastic title "Great Yuan", known retroactively as the "Northern Yuan". The Ming army pursued the Yuan remnants into the Mongolian steppe in 1372, but were defeated by Biligtü Khan Ayushiridara (r. 1370–1378) and his general Köke Temür (d. 1375). In 1375, Naghachu, a Mongol official of Biligtu Khan in Liaoyang province invaded Liaodong with aims of restoring Mongol power in China proper. Although he continued to hold southern Manchuria, Naghachu eventually surrendered to the Ming dynasty in 1387–88. The Yuan loyalists under the Kublaid prince Basalawarmi (the Prince of Liang) in Yunnan and Guizhou were also defeated and killed by the Ming earlier in 1381–82.