exarchatus

Exarchatus is a Latin term used to describe a territorial jurisdiction governed by an exarch in the late Roman and Byzantine imperial system. The word derives from the Greek exarchos, meaning ruler or leader, and conveys the notion of authority exercised across civil and military spheres. In practice, an exarchate functioned as a frontier province with a single high official who combined administrative and military duties, answering directly to the central imperial government rather than to local provincial authorities.

Administratively, the exarchatus typically encompassed a capital city and its surrounding territories. The exarch held sovereign power within the province, coordinating taxation, law, defense, and diplomacy, and often commanding the local garrison. This arrangement aimed to provide centralized control over strategic regions facing external threats and to sustain imperial reach in contested frontiers. The exarchs were usually appointed by and responsible to the emperor, reinforcing imperial unity across distant domains.

In the late antique and early medieval Byzantine world, two major exarchates are commonly cited: the Exarchate of Ravenna in Italy (established in the late 6th century) and the Exarchate of Africa, centered on Carthage (developed during the 7th century). These entities exemplified the model of centralized governance meant to secure western and southern frontiers, coordinate defense against Lombards and other powers, and maintain imperial administration across diverse territories.

The exarchate system declined during the 7th and 8th centuries as external pressures intensified and administrative reforms shifted toward the theme system in the Byzantine Empire. By the high medieval period, the political utility of exarchates had diminished, though the term exarchatus continues to appear in scholarly discussions of late Roman and early Byzantine governance.