In a council of war, Bahram was chosen to lead an army against them and was given the governorship of Khorasan. Bahram's army supposedly consisted of 12,000 hand-picked horsemen. His army ambushed a large army of Turks and Hephthalites in April 588, at the battle of Hyrcanian rock, and again in 589, re-conquering Balkh, where Bahram captured the Turkic treasury and the golden throne of the Khagan. He then proceeded to cross the Oxus river and won a decisive victory over Turks, personally killing Bagha Qaghan with an arrowshot. He managed to reach as far as Baykand, near Bukhara, and also contain an attack by the son of the deceased Khagan, Birmudha, whom Bahram had captured and sent to the Sasanian capital of Ctesiphon. Birmudha was well received there by the Sasanian king (shah) Hormizd IV, who forty days later had him sent back to Bahram with the order that the Turkic prince should get sent back to Transoxiana. The Sasanians now held suzerainty over the Sogdian cities of Chach and Samarkand, where Hormizd minted coins.