The Altan Khans (lit. Golden Khan) ruled north-western Mongolia from about 1609 to 1691 at the latest. Altan Khan of Khalkha also known as Altan Khan of Khotogoid ruled over the Khotogoids in northwestern Mongolia and belonged to the Left Wing of the Khalkha (Eastern) Mongols. Although they claimed to be Khan, Mongolian chronicles call them Hun Taij, which meant noble rank equal to Prince at that time.
After the death of Dayan Khan some time after 1517 his empire was split between his descendents and became a kind of family federation. His grandson, a different Altan Khan (1507–1582) of Tumet drove the Oirats west to Kobdo in western Mongolia. Dayan Khaan's youngest son, Gersendze Huangtaizi, was given lands approximately matching the territory of present-day Mongolia. By the early 17th century most of Outer Mongolia was held by his descendents. These formed four Khanates, from west to east:
The Altyn Khan (great grandson of Geresandza) in the far west.
Dzasagtu-khan, khanate founded by Laikhor-khan, a cousin of the Altyn Khan.
Tushetu Khan at Ulan Bator founded by Abatai, another grandson. This was the senior branch.
Sechen-khan at the eastern end of modern Mongolia, founded by Shului, a great-grandson.
The Altan Khan was important circa 1609-1682. The Tushetu Khan, with his control of the religious capital, was long the leading figure in Khalkha.
In the 17th century, to the west, the Oirat Zunghar Khanate was gradually consolidated; to the north, the Russians increased their hold over the Siberian forests and, to the east, the Manchus moved south to conquer China (Qing Dynasty).
Ubasi Khong Tayiji (Shului Ubasha khongtaiji) (?-1623) was the first to take the name Altyn Khan. About 1609 he occupied the former Oirat heartland around Kobdo and Lake Ubsa Nor. He drove the Oirats west into Dzungaria in 1620 and 1623. Ubasi was killed by the Oirats in 1623 and was succeeded by his son Badma Erdeni Khong Tayiji.
Badma Erdeni Khong Tayiji (1623-?) his son. In 1652, he abdicated the throne and his son Erinchin Lobsang Tayiji succeeded.
Erinchin Lobsang Tayiji (or Lobdzang or Rinchen Sayin Khong Tayiji) (ca.1658-91): In 1662 he attacked, captured and put to death his eastern neighbor, the Dzasagtu Khan. This led the senior Tushetu Khan (Chaghun Dorji) to form a league and drive out the Altan-khan. In 1667 he was captured by Sengge, the Dzungar chief and was handed over to the (next) Dzasagtu Khan. With the help of the Dzungars and Peking (divide and conquer), he was able to reinstate himself, but in 1682 he was captured by the Dzasagtu Khan. In 1691 he, and his khanate, disappear from the records.