Yabghu (Old Turkic: 𐰖𐰉𐰍𐰆, romanized: yabɣu,[1] simplified Chinese: 叶护; traditional Chinese: 葉護; pinyin: Yèhù), also rendered as Jabgu, Djabgu or Yabgu, was a state office in the early Turkic states, roughly equivalent to viceroy.
The title had also been borne by Turkic princes in the upper Oxus region in post-Hephthalite times.
Frequently, Yabgu was a younger brother of the ruling Kagan, or a representative of the next generation, called Shad (blood prince).
[3] As the Khaganate decentralized, the Yabgu gained more autonomous power within the suzerainty, and historical records name a number of independent states with "Yabgu" being the title of the supreme ruler.
One prominent example was the Oguz Yabgu state in Middle Asia, which was formed after the fragmentation of the Second Türkic Kaganate in the 740s.