Diocese

Diocese (Greek, dioikesis, “administration”), in the Christian Church, the territory over which a bishop exercises ecclesiastical jurisdiction. The term was used as early as the time of the Greek orator Demosthenes to signify the treasury or department of finance. But in the organization of the Roman Empire introduced by the emperor Diocletian, the designation diocese was applied to the larger political divisions, which were subdivided into provinces, or eparchies. About the middle of the 5th century, the dioceses of the empire were Asia, Pontus, the East, Thrace, Macedonia, Dacia, Illyria, Italy, Africa, Gaul, Spain, and Britain. The government of the Christian Church, as established by Constantine I, emperor of Rome, adopted this division, and diocese, as well as other terms borrowed from the government of the Roman Empire, passed over into ecclesiastical usage. The term was first applied in an ecclesiastical context to a collection of metropolitan churches, or provinces (parishes), each under the charge of an archbishop. Later applied to a single metropolitanate, or province, it finally came to signify the local jurisdiction of any bishop of any rank, while the term province came to be used for the group of dioceses under the supervision of an archbishop, or metropolitan.