Oirat Mongol Expansion in the 1430s

Timeline

1. 1431–1435Khovd–Altai region · Western MongoliaTogan Taishi led the Four Oirat (Dzungars, Dörbet, Torghut, Khoshut) tribes into a military alliance, unifying the command system of the western steppe. The alliance combined nomadic cavalry with raiding for trade goods, rapidly accumulating military strength.
2. 1434–1438Northern Mongolian Plateau · Mongolian PlateauThe Oirat launched offensives against the eastern Mongol Tatar tribes, repeatedly defeating eastern Mongol leaders such as Arughtai in the mid-1430s and forcing their power northward. The Oirat gradually gained control of vast pasturelands in the western and central Mongolian Plateau, shifting the political center of the steppe westward.
3. 1438–1440Southern steppe–northern edge of the Hexi Corridor · Southern steppeEsen, Togan's son, emerged in the late 1430s, leading Oirat forces south toward the Ming northern defensive line and straining the Ming court's tributary-gift relationship. The Oirat became the greatest northern threat to the Ming in the mid-15th century, and the Uzbek khanate on Central Asia's northern rim was also constrained by their expansion.