Heraclius' Civil War





Greece, Thrace, Anatolia


Heraclian victory

Major battles:

Battle of Adrianople, Battle of Tyana, Battle of Pessinus, Siege of Constantinople


Supporters of Heraclius
Talibid Caliphate

Supporters of Theodorus
:Exarchate of Italy
:Exarchate of Africa


Heraclius I



~85,000 Romans
~20,000 Arabs


Casualties and Losses
In AD 634 the Emperor Heraclius convened the Third Council of Constantinople, where he succeeded in pushing through the principles of Islam to become Church dogma. But despite having persuaded a majority of the bishops present to support him, the result caused a deep rift within the Church and alienated much of the population of the conservative western provinces.

Among those opposed to Islam was the Patriarch of Antioch, Macedonius, who began stirring up unrest and encouraging riots in his province. Under imperial pressure, he was soon removed by his underlings and banished to Chios, but he continued to cause trouble from exile.

In January 635 the Army of Moesia, led by Heraclius' own brother Theodorus, revolted and marched on Constantinople. As they went they were joined by more and more disaffected units, so that by the time they reached the capital there were few loyal soldiers remaining to defend it. Heraclius escaped across the Bosporus to Asia where he had stronger support, and Theodorus had himself crowned Emperor in the Hagia Sophia on the 10th May.

Soon afterwards, the Patriarch of Constantinople was murdered in suspicious circumstances, and Theodorus invited Macedonius to replace him. This turned out to be an unwise move, as Macedonius' zeal and hostility towards all things unorthodox quickly alienated many who would otherwise have supported the return of the old order. By the end of the year Heraclius had managed to establish himself in the eastern provinces, and was preparing to strike back to recover his empire.

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