The Karluks (also Qarluqs, Qarluks, Karluqs, Old Turkic:, Qarluq, Persian: خَلُّخ (Khallokh), Arabic قارلوق "Qarluq") were a prominent nomadic Turkic tribe residing in the regions of Kara-Irtysh (Black Irtysh) and the Tarbagatai Mountains west of the Altay Mountains in Central Asia. They were also known as the Gelolu (simplified Chinese: 葛逻禄; traditional Chinese: 葛邏祿; pinyin: Géluólù, customary phonetic: Gelu, Khololo, Khorlo or Harluut).
They were closely related to the Uyghurs. Karluks gave their name to the distinct Karluk group of the Turkic languages, which also includes the Uyghur, Uzbek and Ili Turki languages. The Karluk language is also known as Chagatai.
Karluks were known as a coherent ethnic group with autonomous status within the Göktürk kaganate and the independent states of the Karluk Yabgu and Karakhanids, before being absorbed in the Chagatai Khanate of the Mongol empire.
Read more about Karluks: Etymology