1911 Encyclopædia Britannica/Eparch
EPARCH, an official, a governor of a province of Roman Greece, ἐπαρχος, whose title was equivalent to, or represented that of the Roman praefectus. The area of his administration was called an eparchy (ἐπαρχία). The term survives as one of the administrative units of modern Greece, the country being divided into nomarchies, subdivided into eparchies, again subdivided into demarchies (see Greece: Local Administration). “Eparch” and “eparchy” are also used in the Russian Orthodox Church for a bishop and his diocese respectively.