Apostolic Exarch

In the Byzantine Empire, an exarch (/ˈɛksɑːrk/; Ancient Greek: ἔξαρχος exarchos) was a governor with extended authority over a province at some distance from the capital Constantinople. The prevailing situation frequently involved him in military operations.

In the Eastern Christian Churches (Eastern Orthodox, Oriental Orthodox and Eastern Catholic), the term exarch has two distinct uses: the deputy of a patriarch, or a bishop who holds authority over other bishops without being a patriarch (thus, a position between that of patriarch and metropolitan); or, a bishop appointed over a group of the faithful not yet large enough or organized enough to be constituted an eparchy/diocese (thus the equivalent of a vicar apostolic).

In the civil administration of the Byzantine Roman Empire the exarch was, as stated above, the viceroy of a large and important province. The Exarchates were a response to weakening imperial authority in the provinces and were part of the overall process of unification of civil and military offices, initiated in early form by Justinian I, which would lead eventually to the creation of the Thematic system by either the Emperor Heraclius or Constans II.

After the dissolution of the Western Empire in the late fifth century, the Eastern Roman Empire remained stable through the beginning of the Middle Ages and retained the ability for future expansion. Justinian I reconquered North Africa, Italy, Dalmatia and finally parts of Spain for the Eastern Roman Empire. However, this put an incredible strain on the Empire's limited resources. Subsequent emperors would not surrender the re-conquered land to remedy the situation. Thus the stage was set for Emperor Maurice to establish the Exarchates to deal with the constantly evolving situation of the provinces.

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