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 was a noble rank equivalent to prince.