At the end of the 3rd century AD, the Roman emperor
Diocletian divided the great Roman province of
Africa Proconsularis into three smaller provinces: Zeugitana in the north, still governed by a
proconsul and referred to as Proconsularis; Byzacena to its adjacent south, and
Tripolitania to its adjacent south, roughly corresponding to southeast
Tunisia and northwest
Libya. Byzacena corresponded roughly to eastern Tunisia or the modern Tunisian region of
Sahel.
Hadrumetum (modern
Sousse) became the capital of the newly made province, whose governor had the rank of
consularis. At this period the Metropolitan Archbishopric of Byzacena was, after the great metropolis
Carthage, the most important city in Roman (North) Africa west of
Egypt and its
Patriarch of Alexandria. The
toponym is believed to derive from the Byzantes or Byzacii, a
Libyan people who lived around the
Gulf of Gabès (Lesser Syrtis). They are called Gyzantes or Zygantes by
Herodotus. == Episcopal sees ==