Leo IV the Khazar

Leo IV the Khazar (Greek: Λέων Δ΄ ὁ Χάζαρος, Leōn IV ho Khazaros; 25 January 750 – 8 September 780) was Byzantine emperor from 775 to 780 AD. He was born to Emperor Constantine V and Empress Tzitzak in 750. He was elevated to caesar the next year, in 751, and married to Irene of Athens in 768. When Constantine V died in September 775, while campaigning against the Bulgarians, Leo IV became senior emperor on 14 September 775. In 778 Leo raided Abbasid Syria, decisively defeating the Abbasid army outside of Germanicia. Leo died on 8 September 780, of tuberculosis. He was meant to be succeeded by his son Constantine VI, but rule instead transferred to his wife Irene, who assumed the role of regent and later empress.

Leo IV
Emperor of the Romans
Icones imperatorvm romanorvm, ex priscis numismatibus ad viuum delineatae, and breui narratione historicâ (1645) (14560071889).jpg
Illustration of Leo IV (left) and his son Constantine VI (right) from the Icones Imperatorum Romanorum (1557), based upon Byzantine coins minted bearing their images
Byzantine emperor
Junior751 – 14 September 775
Senior14 September 775 – 8 September 780
PredecessorConstantine V
SuccessorConstantine VI
Born25 January 750
Died8 September 780 (aged 30)
IssueConstantine VI
DynastyIsaurian Dynasty
FatherConstantine V
MotherTzitzak (Irene of Khazaria)
Isaurian or Syrian dynasty
Leo III 717–741
with Constantine V as co-emperor, 720–741
Constantine V 741–775
with Leo IV as co-emperor, 751–775
Artabasdos' usurpation 741–743
Leo IV 775–780
with Constantine VI as co-emperor, 776–780
Constantine VI 780–797
under Irene as regent, 780–790, and with her as co-regent, 792–797
Irene as empress regnant 797–802
Preceded by
Twenty Years' Anarchy
Followed by
Nikephorian dynasty


Leo IV was born on 25 January 750 AD,[1] to Emperor Constantine V and his first wife, Empress Tzitzak.[2] Because his mother was a Khazar, Leo was given the epithet 'the Khazar'.[3] Leo was elevated to co-emperor in 751, while still an infant.[2] He became emperor on 14 September 775, after Constantine V died while campaigning against the Bulgarian Empire.[4][5]

Leo was by this point suffering from tuberculosis, which, combined with the infancy of his son, Constantine VI, gave two of Leo's half-brothers, the caesares Nikephoros and Christopher, hope of attaining the throne. These hopes were crushed when, in 776, Leo elevated Constantine to caesar, declaring him to be his successor. Shortly after this, Nikephoros and Christopher were discovered conspiring against Leo. Despite public opinion supporting the execution of the pair, Leo instead chose to pardon them, although he did exile several other plotters to Cherson.[3][2][6]

Invasion of the Abbasid CaliphateEdit

Leo launched an invasion against the Abbasids in 778, invading Syria with a force made up of the armies of the multiple themes, including: the Opsikion Theme, led by Gregory; the Anatolic Theme, led by Artabasdos; the Armeniac Theme, led by Karisterotzes; the Bucellarian Theme, led by Tatzates; and the Thracesian Theme, led by Lachanodrakon. Lachanodrakon besieged Germanicia for a time, before he was bribed to raise the siege, and then began to raid the surrounding countryside. The Abbasids attacked Lachanodrakon while he was raiding, but were decisively defeated by several Byzantine armies. The Byzantine generals who led troops during this battle were given a triumphal entry when they returned to Constantinople. A number of Jacobites (adherents of the Syriac Orthodox Church) were taken from Syria and forcibly resettled in Thrace. The next year, in 779, Leo successfully repelled an attack by the Abbasids against Asia Minor.[7]

Death and successionEdit

Leo died of a violent fever, due to his tuberculosis, on 8 September 780. He was succeeded by his son Constantine, with Leo's wife Irene as his regent. In 797, after Constantine had ruled for 17 years, Irene had him blinded, and became the effective monarch and ruling empress.[8][9]



  1. ^ Grierson, Philip (2001). Scritti Storici E Numismatici. Centro Italiano di Studi sull'Alto Medioevo. p. 273. ISBN 9788879882446.
  2. ^ a b c Lawler 2011, p. 186.
  3. ^ a b Bury 2015, p. 478.
  4. ^ Melton 2014, p. 568.
  5. ^ Sophoulis 2011, p. 143.
  6. ^ Finlay 2017, p. 85.
  7. ^ Bury 2015, p. 479.
  8. ^ Melton 2014, p. 569.
  9. ^ Finlay 2017, pp. 85–88.


  • Bury, J. B. (2015). A History of the Later Roman Empire. Cambridge University Press. ISBN 9781108083188.
  • Finlay, George (2017). The Later Byzantine Empire. Merkaba Press. OCLC 1886829.
  • Lawler, Jennifer (2011). Encyclopedia of the Byzantine Empire. McFarland. ISBN 978-0786466160.
  • Melton, J. Gordon (2014). Faiths Across Time: 5,000 Years of Religious History [4 Volumes]: 5,000 Years of Religious History. ABC-CLIO. ISBN 9781610690263.
  • Sophoulis, Panos (2011). Byzantium and Bulgaria, 775-831. Brill. ISBN 978-9004206953.
Leo IV the Khazar
Born: 25 January 750 Died: 8 September 780
Regnal titles
Preceded by Byzantine Emperor
14 September 775 – 8 September 780
Succeeded by
Political offices
Preceded by
Constantine V in 742, then lapsed
Consul of the Roman Empire
Succeeded by
Constantine VI in 782