Claim: In 1439 Toghtoa Bukha became a Khagan, which is a title of imperial rank equal to the status of emperor, he had a title of  Bogd Khagan Taisun of the Northern Yuan.
Evidence: In 1439 Toghan installed Toghtoa Bukha as leader of the eastern Mongols under the title of Bogd Khagan Taisun of the Northern Yuan before the eight white yurts of Genghis Khan. Khagan or Qaghan (Old Turkic: 𐰴𐰍𐰣‎, romanized: Kaɣan, Mongolian: Xаан or ᠬᠠᠭᠠᠨ, romanized: Khaan, Ottoman Turkish: خواقين‎, romanized: Ḫākan, or خوان Ḫān, Turkish: Kağan, Uyghur: قاغان‎‎, ULY: Qaghan) is a title of imperial rank in the Turkic, Mongolic and some other languages, equal to the status of emperor and someone who rules a khaganate (empire).