The Turk Khaganate and the fall of the Eftalites

In the mid-6th century a new state that united the Turkic tribes of the Altai and southern Siberia arose: the Turk Khaganate. Its founder Bumin was proclaimed khagan in 552. Istami led the campaigns to the west and received the title “Yabghu Khagan”; by 555 the Turks had reached the Syr Darya and the Aral Sea. The Sasanian king Khosrow I Anushirvan (531–579), who feared the Eftalites, made a military alliance with the Turks and became Istami’s son-in-law. In the attacks of 563–567 the Eftalite state was defeated: lands up to the southern bank of the Amu Darya went to Iran, and lands along its right bank up to the Caspian Sea passed to the Turks. The khaganate rested on a union of tribes ruled by the khagan; the governor of the ten-arrow people was called yabghu and the commander of ten thousand horsemen shad. Leaving the oasis principalities under local dynasties, the Turks limited themselves to collecting tribute and the yasoq. Because governors wanted independence, the khaganate split in the late 580s into the Eastern and Western Turk Khaganates.