Oirat

The Oirat are the western Mongols; their name joins the Mongolic words for forest and people, their home around the Altai and Khovd lakes. Subdued by Jochi in 1207, they served the Mongol Empire as troops. After the Yuan lost China in 1368 they regrouped as the Four Oirats, including the Dzungar and Khoshut, and with Ming backing eclipsed the eastern Borjigid khans.

Esen Taishi, who ruled from 1438 to 1454, unified the Mongols and in 1449 captured the Zhengtong Emperor at Tumu. The Oirat adopted Tibetan Buddhism around 1615; in the seventeenth century the Khoshut monk Zaya Pandita gave them the Clear Script, based on the Mongolian alphabet.

The tribes fanned out: Güshi Khan led the Khoshuts to conquer Amdo in 1637 and Tibet in the early 1640s; the Torghuts reached the Volga by 1630 as Kalmyks, survivors trekking back to Dzungaria in 1771. The Dzungars built the last steppe empire, with its own guns and laws, until Qing conquest in 1755–1757 destroyed the khanate and many of its people.