The clan was named after a mythical founder Yaglakar Khan[1] or Buk Khan (卜可汗).[2] Initially a part of Tiele Confederation, they carried the hereditary title elteber later as subjects of the Tang dynasty. The first known member of the clan was Tegin Irkin (特健俟斤 *dək̚-ɡɨɐnH ʒɨX-kɨn > Tèjiàn Sìjīn).
By the death of Yaoluoge Achuo in 795, the main line of the Yaglakar clan ceased to exist. However, successive khagans adopted the Yaglakar surname for prestige.[6] The rest of the clan members were exiled to the Tang capital Chang'an. An epitaph was recently found in 2010 in Xi'an which belonged to one of the Yaglakar princes, Prince Gechuai (葛啜王子),[7] younger brother of Yaoluoge Dunmohe[8] who died of cold fever on 11 June 795 and was buried on 28 June 795.
The last member of the clan, Baoguo Qaghan, committed suicide in 1032 after the Ganzhou Uyghur Kingdom was annexed by the Western Xia.[10]Yuri Zuev proposed that the Yaglakar clan survived and eventually became Mongolized under the name "Jalairs".[11]
^Cheng Suluo: "A Study of the Khaganal Genealogy of Ganzhou Kingdom", "On the History of the Tang and Song Dynasties" (Beijing: People's Publishing House, 1994), pp. 140-149. (in Chinese)
^Zuev, Yu A. (2002). Early Turks: Essays on history and ideology. Oriental Studies Institute, Almaty: Daik-Press. pp. 104–105.