Byzantine diplomatic policy towards the steppe peoples generally consisted of encouraging them to fight among themselves.
The Pechenegs provided great assistance to the Byzantines in the 9th century in exchange for regular payments.
Byzantium also sought alliances with the Göktürks against common enemies: in the early 7th century, one such alliance was brokered with the Western Tűrks against the Persian Sasanians in the Byzantine–Sasanian War of 602–628.
The Byzantines called Khazaria Tourkía, and by the 9th century referred to the Khazars as 'Turks'.
During the period leading up to and after the siege of Constantinople in 626, Heraclius sought help via emissaries, and eventually personally, from a Göktürk chieftain of the Western Turkic Khaganate, Tong Yabghu Qağan, in Tiflis, plying him with gifts and the promise of marriage to his daughter, Epiphania.
Tong Yabghu responded by sending a large force to ravage the Persian empire, marking the start of the Third Perso-Turkic War.
A joint Byzantine-Tűrk operation breached the Caspian gates and sacked Derbent in 627.
Together they then besieged Tiflis, where the Byzantines may have deployed an early variety of traction trebuchets (ἑλέπόλεις) to breach the walls.
After the campaign, Tong Yabghu is reported, perhaps with some exaggeration, to have left some 40,000 troops behind with Heraclius.
Although occasionally identified with Khazars, the Göktürk identification is more probable since the Khazars only emerged from that group after the fragmentation of the former sometime after 630.
Some scholars argued that Sasanian Persia never recovered from the devastating defeat wrought by this invasion.

Once the Khazars emerged as a power, the Byzantines also began to form alliances with them, dynastic and military.
In 695, the last Heraclian emperor, Justinian II, nicknamed "the slit-nosed" (ὁ ῥινότμητος) after he was mutilated and deposed, was exiled to Cherson in the Crimea, where a Khazar governor (tudun) presided.
He escaped into Khazar territory in 704 or 705 and was given asylum by qağan Busir Glavan (Ἰβουζήρος Γλιαβάνος), who gave him his sister in marriage, perhaps in response to an offer by Justinian, who may have thought a dynastic marriage would seal by kinship a powerful tribal support for his attempts to regain the throne.
The Khazarian spouse thereupon changed her name to Theodora.
Busir was offered a bribe by the Byzantine usurper, Tiberius III, to kill Justinian.
Warned by Theodora, Justinian escaped, murdering two Khazar officials in the process.
He fled to Bulgaria, whose Khan Tervel helped him regain the throne.
Upon his reinstalment, and despite Busir's treachery during his exile, he sent for Theodora; Busir complied, and she was crowned as Augusta, suggesting that both prized the alliance.

Decades later, Leo III (ruled 717–741) made a similar alliance to co-ordinate strategy against a common enemy, the Muslim Arabs.
He sent an embassy to the Khazar qağan Bihar and married his son, the future Constantine V (ruled 741–775), to Bihar's daughter, a princess referred to as Tzitzak, in 732.
On converting to Christianity, she took the name Irene.
Constantine and Irene had a son, the future Leo IV (775–780), who thereafter bore the sobriquet, "the Khazar".
Leo died in mysterious circumstances after his Athenian wife bore him a son, Constantine VI, who on his majority co-ruled with his mother, the dowager.
He proved unpopular, and his death ended the dynastic link of the Khazars to the Byzantine throne.
By the 8th century, Khazars dominated the Crimea (650–c.
950), and even extended their influence into the Byzantine peninsula of Cherson until it was wrested back in the 10th century.
Khazar and Farghânian (Φάργανοι) mercenaries constituted part of the imperial Byzantine Hetaireia bodyguard after its formation in 840, a position that could openly be purchased by a payment of seven pounds of gold.
Byzantine diplomatic policy towards the steppe peoples generally consisted of encouraging them to fight among themselves. The Pechenegs provided great assistance to the Byzantines in the 9th century in exchange for regular payments. Byzantium also sought alliances with the Göktürks against common enemies: in the early 7th century, one such alliance was brokered with the Western Tűrks against the Persian Sasanians in the Byzantine–Sasanian War of 602–628. The Byzantines called Khazaria Tourkía, and by the 9th century referred to the Khazars as 'Turks'. During the period leading up to and after the siege of Constantinople in 626, Heraclius sought help via emissaries, and eventually personally, from a Göktürk chieftain of the Western Turkic Khaganate, Tong Yabghu Qağan, in Tiflis, plying him with gifts and the promise of marriage to his daughter, Epiphania. Tong Yabghu responded by sending a large force to ravage the Persian empire, marking the start of the Third Perso-Turkic War. A joint Byzantine-Tűrk operation breached the Caspian gates and sacked Derbent in 627. Together they then besieged Tiflis, where the Byzantines may have deployed an early variety of traction trebuchets (ἑλέπόλεις) to breach the walls. After the campaign, Tong Yabghu is reported, perhaps with some exaggeration, to have left some 40,000 troops behind with Heraclius. Although occasionally identified with Khazars, the Göktürk identification is more probable since the Khazars only emerged from that group after the fragmentation of the former sometime after 630. Some scholars argued that Sasanian Persia never recovered from the devastating defeat wrought by this invasion.
Once the Khazars emerged as a power, the Byzantines also began to form alliances with them, dynastic and military. In 695, the last Heraclian emperor, Justinian II, nicknamed "the slit-nosed" (ὁ ῥινότμητος) after he was mutilated and deposed, was exiled to Cherson in the Crimea, where a Khazar governor (tudun) presided. He escaped into Khazar territory in 704 or 705 and was given asylum by qağan Busir Glavan (Ἰβουζήρος Γλιαβάνος), who gave him his sister in marriage, perhaps in response to an offer by Justinian, who may have thought a dynastic marriage would seal by kinship a powerful tribal support for his attempts to regain the throne. The Khazarian spouse thereupon changed her name to Theodora. Busir was offered a bribe by the Byzantine usurper, Tiberius III, to kill Justinian. Warned by Theodora, Justinian escaped, murdering two Khazar officials in the process. He fled to Bulgaria, whose Khan Tervel helped him regain the throne. Upon his reinstalment, and despite Busir's treachery during his exile, he sent for Theodora; Busir complied, and she was crowned as Augusta, suggesting that both prized the alliance.
Decades later, Leo III (ruled 717–741) made a similar alliance to co-ordinate strategy against a common enemy, the Muslim Arabs. He sent an embassy to the Khazar qağan Bihar and married his son, the future Constantine V (ruled 741–775), to Bihar's daughter, a princess referred to as Tzitzak, in 732. On converting to Christianity, she took the name Irene. Constantine and Irene had a son, the future Leo IV (775–780), who thereafter bore the sobriquet, "the Khazar". Leo died in mysterious circumstances after his Athenian wife bore him a son, Constantine VI, who on his majority co-ruled with his mother, the dowager. He proved unpopular, and his death ended the dynastic link of the Khazars to the Byzantine throne. By the 8th century, Khazars dominated the Crimea (650–c. 950), and even extended their influence into the Byzantine peninsula of Cherson until it was wrested back in the 10th century. Khazar and Farghânian (Φάργανοι) mercenaries constituted part of the imperial Byzantine Hetaireia bodyguard after its formation in 840, a position that could openly be purchased by a payment of seven pounds of gold.
Khazars