In 1455 other Oirat tribes overthrew the Choros Khan, Esen Taishi, who had enthroned himself Khagan of the Mongols.
The Khalkha and southwestern Inner Mongolian princes repeatedly raided them from 1552 to 1628, forcing them to migrate further west.
Some of the Choros fled with a group of the Dörbet Oirat northward into Siberia and present-day Barnaul.
[1] The Dzunghar Khanate was ruled by the Dörbet and the Choros, displacing the Khoshut in from their homeland Dzungaria.
Although they reached their peak in the late 17th century, they began to disintegrate after Galdan Boshugtu Khan's wars with the Qing.