Oirat

The Oirats were a western Mongol confederation whose ancestral lands lay around the Altai. After the Yuan dynasty fell, they distinguished themselves from the eastern Mongols as the Four Oirats.

Esen became their leading ruler in 1438 and united Mongolia under his influence. In 1449 he defeated a Ming army at Tumu and captured the emperor Yingzong, whom he released the following year. Esen proclaimed himself Great Khan in 1453 but was killed after a revolt in 1455.