APersonIndependent states
Istemi Yabgu Qaghan
Brother of Bumin Qaghan and ruler of the Göktürks' western wing (552-576): the yabgu who extended the state to the Black Sea and made contact with Byzantium.
After founding the state, Bumin Qaghan entrusted its western part to his brother Istemi. Istemi allied with the Iranian shah Khosrow I, and between 557 and 563 they defeated the Hephthalites together; Sogdia and the lands up to the Oxus passed to the Göktürks.
When Iran blocked the sale of Turkic silk through its territory, Istemi sent the Sogdian Maniakh to Constantinople, and in 568-569 an alliance with Byzantium was formed. Byzantine sources call him Silziboulos. Istemi died in 576; the Orkhon inscriptions name him alongside Bumin as "my ancestor".
Sources
Updated: November 12, 2026