Early military conflicts were a result of the Tang interventions in the rivalry between the Western and Eastern Turks in order to weaken both.

The wars against the Western Turks continued under Emperor Gaozong, and the khaganate was annexed after General Su Dingfang's defeat of Qaghan Ashina Helu in 657.

[1] Emperor Gaozu, Taizong's predecessor, allowed the assassination of a Western Turk khan by Eastern Turkic rivals on November 2, 619.

Disaffected Western Turkic tribes had requested the support of Taizong in Chang'an, who enthroned a new qaghan Irbis Seguy.

[5] The Tang court and the Western Turks began negotiating over the control of five oasis states in the Tarim Basin.

As the oasis state nearest to Tang China, the Chinese constituted a large portion of Karakhoja's population.

The Chinese forces stationed in Gaochang, a short distance away from Karasahr, posed a direct threat to the oasis state.

Led by Commander Guoxiao Ke, protectorate-general of the Anxi Protectorate, the army marched towards Karasahr from Yulduz.

[10][11] The Tang forces mounted a surprise attack at dawn,[11] resulting in the annexation of Karasahr and the capture of its king.

[13] Ashina Helu, a former Tang general in Gansu, fled west and declared himself qaghan of the Western Turks,[17] unifying the Turkic tribes under a single khaganate.

[18] Helu invaded the kingdoms of the Tarim Basin and led frequent raids against bordering Tang cities.

[19] The army departed from Ordos in march and traversed through 3,000 miles of steppes and desert, without stopping by the oasis kingdoms for supplies.

Tang forces captured the leader of the Western Turks and annexed Tokmak, which was transformed into a military base.

In 712, Kul Tigin, son of Ilterish, defeated the remnants of the Western Turks, members of the Turgis confederation.

[32] Central Asian art adopted many Tang Chinese stylistic elements, like the sancai three color glaze used for ceramics.

[33] According to Chinese sources, Turkic states and polities still valued ties with the courts of dynasties in northern China as a form of prestige.

The Qarakhan and Qarakhitay khans held titles that identified them as Tabghach or Khitay, named after kingdoms in northern China.