the circuit or extent of the jurisdiction of a bishop. The word is formed from the Greek *διοικέω*, government, administration, derived from *διοικέω*, which the ancient glossaries render *administro, moderor, ordino*; and hence *διοικέω τῆς πόλεως* the administration or government of a city.

Diocese is also used in ancient authors for the province of a metropolitan.

*Diocesis* was originally a civil government, or prefecture, composed of different provinces.

The first division of the empire into dioceses is ordinarily ascribed to Constantine, who distributed the whole Roman world into four, namely, the diocese of Italy, the diocese of Illyria, that of the East, and that of Africa. And yet long before the time of Constantine, Strabo, who wrote under Tiberius, takes notice (lib. xiii. p. 432) that the Romans had divided Asia into dioceses; and he complains of the confusion which such a division occasioned in geography, Asia being no longer divided by people, but by dioceses, each of which had a tribunal or court, where justice was administered. Constantine, therefore, was only the instigator of those large dioceses, which comprehended several metropolises and governments; the former dioceses only comprehending one jurisdiction or district, or the country which had resort to one judge, as appears from the above passage in Strabo, and also from two in Cicero (lib. iii. epist. ad Famil. 9, and lib. xiii. ep. 67).

Thus at first a province included different dioceses, and afterwards a diocese came to comprehend different provinces. In after times the Roman empire became divided into thirteen dioceses or prefectures; though, including Rome and the suburban regions, there were fourteen. These fourteen dioceses comprehended a hundred and twenty provinces; each province had a proconsul, who resided in the capital or metropolis; and each diocese of the empire had a consul, who presided in the principal city of the district.

On this civil constitution the ecclesiastical one was afterwards regulated; and each diocese had an ecclesiastical vicar or primate, who judged finally of all the concerns of the church within his territory. At present, however, diocese does not signify an assemblage of different provinces, but is limited to a single province under a metropolitan, or more commonly to the single jurisdiction of a bishop.

Brito observes that diocese is properly the territory and extent of a baptismal or parochial church; and hence various authors use the word to signify merely a parish. See Parish.