After the years 558 having fought with the Sasani, the Hazar's (better to say Sabar's) proclaimed to be a tribe dominating over the Caucasian, were well known in Byzantium under the name "Hazar" in 586, but for the same time they were also called "Turks". In Chinese sources they are mentioned as "Turk-Hazar" (T'u-küe Ho-sa-K'o-sa).
These last two records show us that the Hazar's nation had been taken into the land of the Gok-Turk Empire, whose domination had reached to Black Sea in the years of 576, and the usage of the population names fit to the Turkish usage. Thus, the Hazar's formed the outer wing of the Gok-Turk khanate in west. According to the Armenian historical priest Sebeos (VII. Century) and Islamic sources, this situation had last until the 2nd quarter of the 7th decade under the administration of a leader from the Aşına family of the Gok-Turk dynasty and with the power of the West Gok-Turk Khane the Hazar's had given help to Byzantium against the Sasani.
Close to 626, when the Hazar's had come to Georgia and occupied Tiflis by passing Derbend and from there on entered Azerbaijan, Herakleios the emperor of Byzantium who had taken the capitol Sasani-Avar under siege, came to the fronts of Tiflis and was successful to walk into the inner parts of Iran due to the 40 thousand horseman support he had gained after his negotiations with "Yabgu", a Hazar leader - possibly the little brother of the West Gok-Turk Khane Tong Yabgu. After this action Anatolia was freed of the Iranian invasion, the Sa-Sani's no longer were a big state and while the Hazarian commander Çorpan Tarhan successfully carried on his operations, "Yabgu" occupied Tiflis (629) and took some Armenian groups under his protection.