The Western Turkic Khaganate, On Oq (603-657)

From the founding of the Göktürk realm, its western lands were ruled by the descendants of Istemi Khagan. After the civil wars of 593-603 the western wing became a khaganate of its own. Its people were made up of ten tribes, and the union was called "On Oq", the "ten arrows".

The main centre was Suyab in the Chüy valley of today's Kyrgyzstan. Under Tong Yabghu Khagan (618-630) the state reached from the Altai to the Caspian and from the Tarim basin to Tokharistan. In 627 the Western Turks marched into the Caucasus as allies of the Byzantine emperor Heraclius. The Chinese monk Xuanzang met Tong Yabghu near Suyab in 630 and left a description of him.

After Tong Yabghu was murdered, the two wings, the Duolu and Nushibi tribes, fell to quarrelling. In 657 a Tang army defeated Ashina Helu, the last strong khagan. The On Oq tribes later reappeared within the Türgesh Khaganate and the Second Turkic Khaganate.