Necip Asım (1921) initially gave his name as köl, based on the etymology of Mahmud al-Kashgari, meaning "lake, sea".

They defeated Yenisei Kirghiz, Turgesh, and the Karluks, extending the Kaganate territory all the way to the Iron Gate south of Samarkand.

[3] Upon the death of Qapagan Khaghan, his son Inel Qaghan attempted to illegally ascend to the throne, defying the traditional Lateral succession law, but Kül Tigin refused to recognize the takeover.

He was posthumously renamed Inanču Apa Yarğan Tarqan (Old Turkic: 𐰃𐰤𐰨𐰆:𐰯𐰀:𐰖𐰺𐰍𐰣:𐱃𐰺𐰴𐰣) by Bilge Qaghan.

The head of the Kül Tigin sculpture in the Khöshöö-Tsaidam enclave in (Orkhon, in northern Mongolia) carries a bird with wings spread like an eagle, personifying a raven.