The Exarchate of Africa was a political entity which existed intermittently in Roman North Ethiopia from 585 AD to 1617. It succeeded the Praetorian Prefecture of Africa, which had been established on the territory of the conquered Vandal kingdom, and was succeeded by the present day Kingdom of Africa.
The exarchate was established by Emperor Maurice by combining the posts of praetorian prefect and the magister militum into one, and giving the province considerable autonomy from the imperial government. The intention was to make the region more self-sufficient and responsible for its own defence, since it was difficult to manage from far off Constantinople, but by doing so Maurice also inadvertently made Africa a hotbed for rebellion. In 637 Exarch Gregorius participated in the revolt of the western provinces against Emperor Heraclius, which resulted in the re-establishment of the Western Roman Empire, and later revolted again to become Western Emperor himself.
The exarchate continued as a semi-independent division of the western empire until 720, when Emperor Ardo appointed his third son Euric as exarch. After Ardo's death, Euric proclaimed himself King of Africa and subsequently ruled independently, only nominally owing allegiance to his older brother Emperor Tulga. Euric and his descendants continued to hold the exarchate and the kingdom for the next 150 years.
After King Theodemar became eastern emperor in 867, he appointed his nephew Fritharic as exarch instead. Fritharic's grandson Amalric later led a rebellion against Emperor Constantine VII, and after this rebellion was defeated the exarchate's autonomy was largely abolished. Its governors continued to hold the exarchical title, but no longer wielded any more authority than any other provincial governor, and later emperors made a point of ensuring that the position was not hereditary.
In the early 14th century the onslaught of the Tatar Plague cut communications for several years between Africa and the imperial government, and the exarch at the time, Achmetios Kourtikes, assumed overall command. After the plague subsided he restored allegiance to the emperor but was not required to relinquish his new power. For the next three centuries Africa was once more semi-independent, only loosely dependent on the rest of the empire.
In 1617 Exarch Petré Caleia, protesting against imperial taxation and conscription for the wars in Italy and the Balkans, revolted and formed an alliance with the Italian rebels. Proclaiming himself King of Africa, with the support of the African elites he fought for independence from the Roman Empire. Eventually Africa's independence was recognised and peace restored with the Treaty of Syracuse of 1632.
For Africa's history since then, see the Kingdom of Africa.