The crisis that affected the Roman empire in the second half of the third century did not spare Egypt, and it led to comprehensive reforms by in the fields of government, economy, and ideology. Among other measures, the provinces were divided and their number thus considerably enlarged. These measures, accompanied by the separation of civil and military authority in the individual provinces, were taken to lessen the danger of usurpations, which had been a recurrent feature of the preceding decades. At the same time, the fragmentation of the provinces aimed at closer control and greater efficiency of financial administration and taxation, every province being placed under the civil authority of the provincial governor (praeses, iudex). These general principles applied also to the former province of Egypt, which was now subdivided into several provinces.

The exact date of Diocletian’s provincial reform is still debated: 297/298 or, as suggested by Barnes, as early as 293 (1982, pp. 224f.). There is no ancient source giving the date and details of this reform. The facts have to be reconstructed from later lists (see Eadie, 1967) and from isolated mentions in literary texts, inscriptions, and papyri. The number, designation, and area of the newly created provinces in Egypt underwent several changes in the course of the fourth century. These cannot be dealt with here in detail; only the main features will be mentioned. Thebais, corresponding to Upper Egypt, became a separate province.

The other provinces of Egypt derived their names from the tutelary deities of the Tetrarchy: Aegyptus Iovia (with Alexandria) and Aegyptus Herculia, encompassing Middle Egypt and the eastern Delta. The existence of a province Nea Arabia in Egypt is disputed (cf. The Oxyrhynchus Papyri, Vol. 50, no. 3574, with the commentary of J. R. Rea). In 341, Aegyptus Herculia (perhaps at some time [partly?] identical with Aegyptus Mercuriana; see Thomas, 1984) was replaced by the province Augustamnica, from which Middle Egypt was detached as the province Arcadia about 386. Thebais was subdivided into two provinces (first at the end of the third, then again in the sixth century): Thebais Inferior and Thebais Superior.

At the head of Aegyptus was the praefectus augustalis in Alexandria (see PREFECT), whereas the other Egyptian provinces were administered by praesides (superintendents). Both the prefect and the praesides were purely civilian authorities; the military command rested with the dux, attested in 308/309 at the head of both Egypt and the provinces of Libya Inferior and Libya Superior, that is, Pentapolis (cf. Barnes, 1982, p. 211).

It is interesting to note that the same area—Egypt and the two provinces of Libya—was under the authority of the Alexandrian bishop (cf. canon 6 of the Council of Nicaea). The military command structure was later reshaped with the nomination of a military commander (comes rei militaris) and two duces, of the Thebaid and of Libya.

As a consequence of Diocletian’s reform, Egypt lacked a central civil authority of its own. With the two Libyas, the provinces into which Egypt was now subdivided formed part of the dioecesis Oriens and were administered by the civil head of this diocese, the vicarius in Antioch on the Orontes, who functioned as a deputy of the praefectus praetorio in Constantinople. About 381, or perhaps by 371 (cf. De Salvo, 1979), Egypt became a diocese comprehending all Egyptian and Libyan provinces under the central authority of the praefectus augustalis in Alexandria. The administrative unity of Egypt was thus restituted within the frame of the diocese.

At the same time, canon 2 of the Council of Constantinople (381) confirmed the jurisdiction of the Alexandrian bishop over all bishops in the civil diocese of Egypt. The unity of Egypt on both the political and the ecclesiastical level was an important element in the evolution of Christian Egypt and in its troubled relations with Constantinople.

The fifth century, unfortunately, is marked by a serious paucity of papyri concerning the public administration. This period must have witnessed profound changes in the administration, economy, and society of Egypt, details of which we cannot specify but results of which become obvious in the sixth century with its abundance of papyri and legal texts.

The reforms of Emperor Justinian (527-565) pertaining to Egypt resulted from the troubled state of affairs in that country, both from raids by desert tribes and from unrest in Egypt proper, exacerbated by the of taxation and by religious conflicts. Constantinople supported the Melchite patriarchs in Alexandria, whereas the majority of the Egyptian population had defended monophysitism since the Council of Chalcedon (451).

With Edict XIII (538/539 or, less probably, 553/554; cf. Remondon, 1955), Justinian intended to put an end to the administrative chaos in the Aegyptiaca dioecesis, above all to secure the tax income and the grain supply from Egypt to Constantinople. In order to strengthen the efficiency of the administration, the duces were now invested with both civil and military authority, the praesides becoming their civil deputies. The Egyptian diocese was placed under the central authority of the praefectus praetorio in Constantinople and divided into a plurality of ducal territories (chorai), corresponding more or less to the old provinces: Aegyptus, Augustamnica, Arcadia, Thebais, Libya.

The dux augustalis of Aegyptus, residing in Alexandria, was endowed with higher authority, since he was responsible for the transport of grain from Egypt to Constantinople. The ducal territories of Egypt sometimes comprehended several eparchiae (see EPARCHY), each with a praeses at its head; these were subdivided into pagarchiae administered by pagarchs (see PAGARCH).


  • Barnes, T. D. The New Empire of Diocletian and Constantine, pp. 211f., 224f. Cambridge, Mass., and London, 1982.
  • Bowman, A. K. Egypt after the Pharaohs: 332 B.C.-A.D. 642. From to the Arab Conquest. London, 1986. See p. 79, fig. 4, for a table showing the divisions of Egypt for the period 295-560.
  • Eadie, J. W. The Breviarium of Festus: A Critical Edition with Historical Commentary, pp. 154-71. London, 1967. Contains the provincial lists.
  • Jones, A. H. M. The Later Roman Empire, 284-602. A Social, Economic, and Administrative Survey, pp. 1451-61. Cambridge, 1964. Discusses the dioceses and provinces.
  • Jones, A. H. M.; J. R. Martindale; and J. Morris. The Prosopography of the Later Roman Empire, 2 vols. Cambridge, 1971-1980. The provincial governors and Egypt are treated in Vol. 1, pp. 1098f., and Vol. 2, pp. 1282f.
  • Lallemand, J. L’administration civile de l’Egypte de l’avènement de Dioclétien à la création du diocèse (284-382). Contribution à l’étude des rapports entre l’Egypte et l’Empire à la fin du IIIe et au IVe siècle, pp. 41-57. Brussels, 1964.
  • Papyri from Panopolis in the Beatty Library Dublin, ed. T. 1964. Skeat. Dublin, 1964. See pp. XV-XXI for the division of Egypt.
  • Rémondon, R. “L’Edit XIII de Justinien a-t-il été promulgué in 539?” Chronique d’Egypte 30 (1955):112-21.
  • Rouillard, G. L’administration civile de l’Egypte byzantine, 2nd ed. Paris, 1928.
  • Salvo, L. de. “La data d’istituzione delle provincie d’Aegyptus e d’Aegyptus Herculia.” Aegyptus 44 (1964):34-46. Cf. Oxyrhynchus Papyri, Vol. 51, no. 3619 (London, 1984) for the first contemporary evidence of the existence of Aegyptus Iovia.
  • . “Anchora sull’istituzione della dioecesis Aegypti.” Rivista storica dell’antichità 9 (1979):69-74.
  • Thomas, J. D. “Sabinianus, praeses of Aegyptus Mercuriana?” Bulletin of the American Society of Papyrologists 21 (1984):225-34.