2nd Kokturk Khaganate: Why and How Was It Established?

Before the establishment, although there were prominent rebellions as mentioned such as Tardu’s attempt and the head of the Ashina clan Ashina Funian’s attempt to gain independence back from the Tangs, Turkic tribes had to live under the Tang rule for a couple of decades. Upon the failed uprising of Funian, Ilterish Kutluk Qagan went against the Tang afterward. After gathering an armed force of approximately five thousand Turkic warriors, some of whom also had served under Funian in his uprisings, the great commander began his military attacks, primarily concentrated on attacks against the Tang forces and the Uyghurs (Nine Oguz) confederation to the north.

The Tonyukuk inscription records that it was Tonyukuk himself who enthroned Ilterish Qagan. According to Chinese resources, Ilterish Qagan later proclaimed Qapgan Khan as the head of the military and his son Inal as the yabgu, governor of the eastern region of Kokturks.

On July 12, 682, the Turks launched their first assault on the Tang border territories, invading the Lan Prefecture and even taking the prefect prisoner and sentencing him to death. Due to the bad weather conditions in their headquarters, the Turks began raiding modern-day Jinzhong's northern borders half a year later than had been planned. In response to all these attacks, the military general was given the responsibility of defending Shandong from Turks. This resulted in a battle between the two military forces that ended with the Turks' loss. However, the Turk forces resumed their attacks and took over two cities by March 683 and besieged Chanyu Province the following month.

In 684, Ilterish Qagan shifted his focus to the steppe and launched a military campaign against the Uyghurs. After the Eastern Turks were subjugated by the Chinese in 630, the Uyghurs confederation had taken control of and established dominance over Ötüken, which held historical and symbolic significance as the ancestral heartland of the Turks. As such the reconquest of Ötüken was necessary for Ilterish Qagan to consolidate his authority and impose himself as the worthy ruler of the steppe, and true qagan of the Turks and steppe nomads. It notes that a deserter from the Uyghurs informed the Turk leaders that the Qagan of the Uyghurs had sent letters to the Tang and Khitans, requesting to form a tripartite alliance against the expanding Kokturks. After learning of this, the adviser and general Tonyukuk informed and advised Ilterish Qagan to first attack the Uyghurs rather than the Uyghurs attacking them beforehand. Thus Kokturks marched to Ötüken and defeated a force of 3,000 Uyghur warriors.

Upon the successful reclamation of Ötüken in 685, the Kokturks encouraged the other Turkic tribes under the Tang rule to rebel against the Tang government, which the Tang perceived as yet another uprising. In response, the Tang dispatched 30,000 troops to suppress the Uyghurs. The Uyghur tribes who had previously surrendered to the Tang during the earlier campaign, were resettled. However, certain families among Uyghurs continued to actively rebel and not give up, prompting the Tang to send another general to the area and suppress the rebellion