His title was Kutluk Boyla during Second Turkic Khaganate. He was a son of Yaoluoge Hushu. His father was the chieftain of Yaglakar clan and made numerous raids into Tang China. At one point he was able to ambush Jiedushi Wang Junchuo killing him and wounding Niu Xianke in 727. He succeeded his father at some point after 727. After Bilge Qaghan died, a factional struggle arose within the ruling Ashina clan. An alliance of Basmyls, Uyghurs and Karluks overthrew Göktürks and in the spring of 745 killed the last Ozmish Qaghan. At first, the Basmyl chief was elected a Kaghan titled Ilterish Kaghan, but he was soon overthrown by the allies, who elected Kutlug Boyla as Kutlug Bilge Kaghan.
Reign
After coming to power in 744, Kutlug Bilge Kaghan moved his court to Khar Balgas in the Orkhon valley. In foreign policy, Kutlug Bilge Kaghan maintained alliance with the Tang China. He was created Prince of Fengyi and Huairen Khagan. In 745 Uighurs defeated last Turkic Kaghan Baimei Khagan, and Kutlug Bilge Kaghan ordered to send his head to Chang'an, after which the Tang Emperorgenerously thanked him with entitling him "Supernumerary General-in-chief of Left Courageous Guard". For the next two years, the Uighur power continuously expanded, although its control did not reach the size of the Turkic Khaganate. He died in 747 and left his son Tay Bilge Tutuq as heir to throne, however his other son Bayanchur Khan was killed him and usurped the throne. He had another son - Tun Bagha Tarkhan who later rose to be a khagan as well.
Reorganized tribes
At first he proclaimed himself as Tokuz Oghuz khagan. Nine tribes included Dokuz Oghuz, which were the Khaganal clan Yaglakar and eight Uighur tribes known in Chinese rendering:
Huduoge 胡咄葛
Guluowu 啒罗勿
Mogexiqi 貊歌息讫
A-Wudi 阿勿嘀
Gesa 葛萨
Huwasu 斛嗢素
Yaowuge 藥勿葛
Xiyawu 奚牙勿
According to Edwin Pulleybank six Tiele tribes in the confederation - Bukut, Hun, Bayegu, Tongren, Syge and Qibi had an equal status with the Uighurs ; the reduced Basmyls numbered eight tribes, and Karluks had three tribes called Uch-Karkuk. However, according to Haneda Toru, Dokuz Oghuz was included in Uighurs. Eleven tribes of the Basmyls and Karluks had a lower status, and were staged as vanguard of the Uighur army. Later the Abusi and Gulunwugu were also added.