戴克里先在284年將行省數量增加到47個，以加強中央政府的控制，使得地方徵稅更加容易，[34]讓行省總督在人口較少的行省里有更充足的時間履行職責。[35]到戴克里先統治末期行省數量增加到了104個。這些行省分別被劃分到12個管區下（這一過程可能是在戴克里先統治末期而不是之後完成的。根據《維羅納職官表（英語：Laterculus Veronensis）》記載，意大利管區有兩位代理官）。根據大約在395年出版的《百官志》記載：到327年，默西亞管區一分為二（北部的達契亞管區（英語：Diocese of Dacia）和南部的馬其頓管區（英語：Diocese of Macedonia））：在370或380年，從東方管區中分出埃及管區，管區數量從12個增加到了14個。意大利管區也被一分為二（北部的補給意大利管區和南部的直轄意大利管區）：代理官駐紮在羅馬時意大利大區總長通常在米蘭，而當總長移駐到潘諾尼亞管區的錫米烏姆時代理官則駐紮於米蘭。[36]高盧管區的特里爾一直是高盧大區總長的駐地，後遷移至阿爾勒。君士坦丁堡（359年才被正式定為第二首都）自330年亦或是395年（337-380年，皇帝僅駐紮在君士坦丁堡11年）起就一直是東方大區的首府。[37]按下轄行省數量（不是管區面積）來算，最大的管區是東方管區，下轄16個行省；最小的管區是不列顛管區，僅下轄4個行省。改革的另一個結果就是帝國官僚機構規模的猛增，其職員專業化程度也大大提高，幾乎全由領取俸祿的自由民擔任。當然按照現代標準，帝國官僚規模依舊很小，5000萬到6000萬人口中僅有三到四萬官員（不包括皇室財產部在地方上的管理人員）。[38]
行政總理（magister officiorum）的職位原為新禁衛軍（Scholarian），君士坦丁一世解散舊禁衛軍（Praetorian Guard/cohortes praetoriae）後建立的精銳衛隊）中護民官頭銜的指揮官，是底層軍事文官。君士坦丁一世在312-313年間將其改為護民官頭銜的帝國書記長（head of the imperial secretariats）。而總理（「magister」，正式頭銜全稱：行政總理兼護民官「tribunus et magister officiorum」）的附加頭銜則是319年首次出現。皇帝還任命行政總理掌管負責帝國信使團，由騎兵組成的政府代理官（英語：Agentes in rebus）（agentes in rebus）。君士坦丁一世在325-326年間解除了總長對行政總理的全面控制，與此同時還為皇帝的親信設立了伯爵頭銜。[90]此後總理成為負責國安、行政監督和通信的大臣。[91]
Constantin Zuckerman, 'Sur la liste de Verone et la province de Grande Armenie, la division de l'empire et la date de création des dioceses, 2002 Travaux et Memoires 12 Mélanges Gilbert Dagron, pp. 618-637 argues for a decision to create diocese by Constantine and Licinius at the meeting in Milan in February 313; since 1980 several scholars have suggested later dates (303, 305, 306, 313/14) than the traditional date of 297 set by Mommsen in the late 19th century
For a recent discussion, Laurent J. Cases, Historia 68, 2019/3 353-367, pp. 354-356, who reports the weight of scholarly opinion is still for 297 for which there is scant evidence "while Diocletian probably did increase the number of agentes vices praefectorum, Constantine created the vicariate in the year 313"
David Potter suggests Constantine in expanding the number of prefects to 4 in 330 intended to recreate the Tetrarchy with prefects rather than co-emperors and their lieutenants, the Caesars, Divisio Regni 364, East and West in the Roman Empire of the Fourth Century an End to Unity, Ed. Roald Dijkstra, Sanne van Poppel, Danielles Slootjes, 'Measuring the Power of the Roman Empire,' p. 44, Radboud Studies in Humanity Vol 5. 2015
The Cambridge Companion to the Age of Constantine, Ed. Noel Lenski, 'Bureaucracy and Government,' Christopher Kelly, pp. 186-187, 201-202, states they were not the four fully developed prefectures the 5th-century writer Zosimus had in mind as existed in 395 - Porena opts for fully operational from 325, p. 201, footnote 15ISBN978-0-521-52157-4; there were three prefects in 325 - in Trier, in Italy and one with Constantine; and four in 331, five from 335-337; cf. Timothy Barnes who argues that the later Constantinian prefects are more expressions of the emperor's dynastic aims than definitively administrative in character: Constantine: Dynasty, Religion and Power in the Later Roman Empire, 2011, pp. 290-293 ISBN978-1118782750; previously prefects were personal, i.e. attached to the office of the emperor and not territorially defined
Pat Southern, The Roman Empire from Severus to Constantine, 2001 p. 165 ISBN0-415-23944-3; The Cambridge Companion to the Age of Constantine, Ed. Noel Lenski, 'Bureaucracy and Government,' Christopher Kelly, pp. 185-187, 201-202ISBN978-0-521-52157-4
Pat, Southern, The Roman Empire from Severus to Constantine, 2001 p. 165 ISBN0-415-23944-3; M.F. Hendy, Studies in the Byzantine Monetary Economy, 1985 300-1450, pp. 373-377, "independent ministries" until mid-5th centuryISBN978-0521088527; Jacek, Wiewiorowski The Judiciary of Diocesan Vicars in the Later Roman Empire, 2016, p. 83, "the responsibility of the vicar was to exercise control of the civilian administration in the diocese;" L.E.A. Franks, review of The Judiciary of Diocesan Vicars in the Later Roman Empire, Jacek Wiewiorowski 2016 ISBN978-83-232-2925-4 in Byzantinische Zeitschrift 206 Vol 109 Part 2 pp. 988-994 {ISBN|978-83-232-2925-4}}
A.H.M. Jones, Later Roman Empire, Vol ! 1964, p, 47 "The vicars seem to have deputized for the praetorian prefects in all their manifold functions"; L.E.A. Franks, review of The Judiciary of Diocesan Vicars in the Later Roman Empire, Jacek Wiewiorowski 2016 ISBN978-83-232-2925-4 in Byzantinische Zeitschrift 206 Vol 109 Part 2 pp. 990-991
The Cambridge Companion to the Age of Constantine, Ed. Noel Lenski, 'Bureaucracy and Government', Christopher Kelly, pp. 185 ISBN978-0-521-52157-4; also for one discussion - Migl, Joachim, Die Ordnung der Amter Prätorianerpräfektur und Vikariat in der Regionsverwaltung des Römischen Reiches von Konstantin bis zur Valentinianischen Dynastie, 1994, pp. 64-68; A. Pignaniol, L'empire chretien, 1972, p. 354, "Ils ne dépendent pas des préfets du prétoire mais directement de l'empereur, et l'on fait appel de leurs décisions judiciaires à l'empereur; appeals from their verdict went straight to the emperor, Theodosian Code, 11, 30, 16 (331); but cf. in a law of 328 CTh. 11, 16, 4 addressed to Aemilianus Constantine refers to "your vicars." Prefects could not overturn the decision of vicar except on appeal; and the authority of vicars was not derivative from prefects but a share of it given to them in their own right by the emperor, CTh. 1, 15, 7, 377, "the dignity of vicar by its very name indicates that it assumes a part (of the prefecture) that it often has the power if our inquiry and is accustomed to represent the reverence of our judgment;」 Cassiodorus, 「Tu autem vicarius dixeris et tua privigelia non reliquia, quando propria est jurisdictio quae a principe datur. Habes enim cum praefectis aliquam portionem,」 6, 15 - Moreover the you will have been designated vicar and your prerogatives (are) not unchanged, when the jurisdiction which is given by the emperor is his own. For you have with prefects some portion
Giardina, Andrea, Aspetti della burocrazia nel basso impero, Edizioni dell』Atneo & Bizzarri, 1977, pp. 45-93 who describes the empire-wide placement of agents in major cities as a web that connected together the administrative 'nodes' located in the larger towns and cities, p. 71; Christopher Kelly, Ruling the Later Roman Empire,2004, p. 206, 210; Jones, Later Roman Empire, 1964 pp. 103-104, 128; Kelly in Cambridge Companion to the Age of Constantine, pp. 188-190
there was in addition a 'rationalis' for Sardinia and Corsica, and Sicily (although only a province - perhaps a scribal error or elevation in status, and one each for Numidia and Africa, two in the diocese of Pannonia, A.H.M. Jones, Later Roman Empire, 1964 p. 48 and from the Notitia Dignitatum circa 395 AD.; usually there were prefects in Gaul at Trier, northern half of the diocese of Italy in Milan; in the Balkans at times stationed in Serdica, Thessaloniki, or Sirmium and for Oriens at Constantinople or some other city; R. Delmaire, Les largesse sacres et res private, Latomus, 1989, pp. 171-172, 181; the RP regional managers was subordinate to the SL until sometime in the 350s during the reign of Constantius II; they always worked closely together sometimes substituting for each other, Jones op. cit. p. 1414-1416; Delmaire, p. 189; and in the West part of the RP's revenue went to the SL, Delmaire, chapter on 'Tituli Largionales;' King, C.E., Ed., Imperial Revenue, Expenditure and Monetary Policy in Fourth Century A.D., The Fifth Oxford Symposium and Monetary History, BAR International Series 76, 1980, chapters on The Res Privata by F. Millar and the SL by C. E. King
Noel Lenski, Failure of Empire, 2002, ISBN978-0-520-23332-4; M. Malcolm Errington, Roman Imperial Policy from Julian to Theodosius, 2006, pp. 261-264' Jones, pp. 405-410
Jacek Wiewiorowski, The Judiciary of Diocesan Vicars in the Later Roman Empire, English Edition 2016, pp. 292-293, 297 ISBN978-83-232-2925-4;R. Malcom Errington, Roman Imperial Policy from Julian to Theodosius, 200, pp. 3-4 pp. 261–262 ISBN978-0-8078-3038-3; L.E.A. Franks, review of The Judiciary of Diocesan Vicars in the Later Roman Empire, Jacek Wiewiorowski 2016 ISBN978-83-232-2925-4 in Byzantinische Zeitschrift 206 Vol 109 Part 2 pp. 988–994
Jones, Later Roman, Empire; 1964, pp. 207-208, 235, 460-61; L.E.A. Franks, review of The Judiciary of Diocesan Vicars in the Later Roman Empire, Jacek Wiewiorowski 2016 ISBN978-83-232-2925-4 in Byzantinische Zeitschrift 206 Vol 109 Part 2 p. 992
Roland Delmaire Les largitiones sacrees et res private, Latomus, 1989, pp. 703-714 ISBN978-272-83061-38; Jones, The Later Roman Empire, 284-602, pp. 280-283 ISBN0-8018-3353-1; L.E.A. Franks, review of The Judiciary of Diocesan Vicars in the Later Roman Empire, Jacek Wiewiorowski 2016 ISBN978-83-232-2925-4 in Byzantinische Zeitschrift 206 Vol 109 Part 2 pp. 988-994
Discussed in Zuckermann; Joachim Migl, Die Ordnung der Amter des Pratorianerprafaktur und Vicariat in der Regionsverwaltung des Romischen Reiches von Konstantin bis zur Valentinianischen Dynsatie, 1993. pp. 54-58; Jacek Wiewiorowski, The Judiciary of Diocesan Vicars in the Later Roman Empire, English Edition 2016, pp. 52-46 ISBN978-83-232-2925-4; Timothy Barnes who now opts for 313/14 in Constantine: Dynasty, Religion and Power in the Later Roman Empire, 2011 pp. 177-178 and in numerous other sources from the late 19th century onwards. Wiewiorowski tabulates dates chosen by scholars in a published paper delivered in Nish in April 2013. By year: 297: Pallu de Lessert, 1899; Kornemann, 1905; Seston, 1946; Ensslin, 1958; Scheurmann, 1960; Jones, 1964; De Martino, 1967; Guademet, 1967; Arnheim, 1970; Hendy, 1972; Christol, 1977; Barnes, 1982; Chastagnol, 1985; Hendy, 1985; Sargenti, 1986; Bleckman, 1997; Carrie & Rouselle, 1999; Kuhoff, 2001; Bowman, 2005; Lo Cascio, 2005; Kulikowski, 2005; Demandt, 2007; Franks, 2012. 303: De Vita Evrard, 1985. After 306: Cuq, 1899; Potter, 2004 306-313: Porena, 2004 +312: Migl, 1994, 313/14; Noetlichs, 1982; Zuckerman, 2002; for a recent discussion, Laurent J. Cases, Historia 68, 2019/3 353-367, pp. 354-356, who reports the weight of scholarly opinion is still for 297 for which there is scant evidence "while Diocletian probably did increase the number of agentes vices praefectorum, Constantine created the vicariate in the year 313"
Ulpian, jurist during the Severan Dynasty 192-235, 「agens vices praefectorum ex mandatis principis cognoscet」 and 「Et is cui mandata iurisdicito est fungetur vice eius qui mandavit, non sua, Dig. II, 1, 16; 「A praefectis vero praetorio vel eo, qui vice praefectis,」 XXXII, 1, 4.; Cledonius 5th century grammarian in Constantinople, 「Saepe quaesitum est utrum vicarius dici debeat is qui ordine codiclliorum vices agit amplissimae praefecturae; ille vero cui vices mandatur propter absentiam praefectorum, non vicarius sed vices agens; non praefecturae sed praefectorum dicitur tantum,」 in Grammatici Latini. V. 13
Roland Delmaire, Les largesses sacres et res private, Latomus, 1989, pp. 171-172, 181, the model is the pre-existing fiscal district of Egypt, Cyrenaica and Crete (detached in 294 and tied to Achaia)ISBN978-272-83016-38
Delmaire, pp. 197, 199 204-204, 245..."the power of the 'rationales' did not cease to be degraded for the 4th century after reaching the apogee of their power between 285-320. At their creation, they were omnipotent in fiscal matters of the diocese but lost it to the advantage of the governors concerning the Annona, cursus publicus and in general all that part of the fiscal (regime) entrusted to the prefects," trans. from the French, p. 204
Diocletian's system was characterized by indiction, a published schedule of budgetary requirements within a given period and census - indiction did not take into account ability to pay, Roger Rees, Diocletian and the Tetrarchy, 2004, p. 38, ISBN07486-1661-6, the system was distributive not contributive which is based on ability to pay; Other Means - Clyde Pharr, The Theodosian Code, 2001 12th Edition, p. 596 ISBN978-1-58477-146-3: (re)appraise the measured assessible land and set the rates, 'censitor'; adjust inequalities and inequities in the tax assessments, 'peraequator'; inspect the taxable land to determine rates, 'inspector' who was a check on the 'censitor'; examine, revise and re-allocate rates on individual possessions,' discussor'; Jones, Later Roman Empire, p. 449; It’s amazing but until the reign of Diocletian the Empire had no global budget! This was due to the 「inelastic fiscal structure of the empire which relied on fixed levies, not production, and which had not been adjusted form the foundation of the empire," Jones, p. 9; also in David, S. Potter, The Roman Empire at Bay, AD 180-395, 2004, pp. 59, 398, also Diocletian's reforms introduced "regularity assessment was the evident effort to impose coherent units of extraction across all provinces," p. 334; 「A fundamental problem of state finance had been that taxes had been cumbrously expressed in terms of fixed amounts of money, which produced inadequate income in periods of currency inflation, or as percentages, where ignorance of the sums being taxed meant that the state could not predict how much a particular tax would bring in.」— Peter Salway, The Oxford Illustrated History of Roman Britain, 1993, p. 234 ISBN0-19-822984-4; for an excellent of description of the later imperial tax regime, Cam Grey, Constructing Communities in the Late Roman Countryside, 2011, pp. 178-197 ISBN978-1-107-01162-5
for discussion of the range of Diocletian's reforms -Jones, The Later Roman Empire. Vol. I, pp. 42-50, 101-102, 449 ; The Cambridge Companion to the Age of Constantine, Ed. Noel Lenski, 'Bureaucracy and Government,' Christopher Kelly, pp. 183-92 ISBN978-0-521-52157-4; David S. Potter, The Roman Empire at Bay 180-395, 2004, pp. 367-377 ISBN0-415-10058-5; Pat Southern, The Roman Empire from Severus to Constantine, 2001 pp. 153-167 ISBN0-415-23944-3; Roger Rees, Diocletian and the Tetrarchy, 2004, ISBN0-7486-1661-6; M.F. Hendy, Studies in the Byzantine Monetary Economy, 1985 300-1450, pp. 373-377 ISBN978-0521088527
the rise of the prefectures as administrative dates from the Valentinian Dynasty post-364 esp. the build-up of Constantinople as the seat of government in the East beginning under Valens, 364-378, even though he spent almost no time there, and which was finally achieved by Theodosius I, 379-395, Errington, p. 262
Jones, p. 371, "grand vizier;" Kelly, pp. 186; David S. Potter, The Roman Empire at Bay 180-395, 2004, pp. 367-377 ISBN0-415-10058-5; Pat Southern, The Roman Empire from Severus to Constantine, 2001 pp. 153-167 ISBN0-415-23944-3
CAH, pp. 284-286, 319 in another theory it was not a special tax but part of the normal tax earmarked for the army p. 381 overseen by vicars p. 181; Pat Southern and Karen R. Dixon, The Late Roman Army, 1996, pp. 62-63 ISBN0-300-06843-3; Cam Grey, Constructing Communities in the Late Roman Countryside, 20111, pp. 178-197 ISBN978-1-107-01162-5 the Annona Militaris is one example of a change from ad hoc and arbitrary to fixed, permanent charges within total budgetary process in the modern sense and, for which, vicars were responsible in their dioceses
The Cambridge Ancient History XII, 2001, pp. 170-183, 'The new state of Diocletian and Constantine from the Tetrarchy to the reunification of the empire'ISBN978-0-521-30199-2; Jones, The Later Roman Empire. Vol. I, pp. 42-50, 101-102, 449 ISBN0-8018-3353-1; The Cambridge Companion to the Age of Constantine, Ed. Noel Lenski, 'Bureaucracy and Government,' Christopher Kelly, pp. 183-192 ISBN978-0-521-52157-4; David S. Potter, The Roman Empire at Bay 180-395, 2004, pp. 367-377
David Potter suggests Constantine in expanding the number of prefects to 4 in 330 intended to recreate the Tetrarchy with prefects rather than co-emperors and their lieutenants, the Caesars, Divisio Regni 364, East and West in the Roman Empire of the Fourth Century an End to Unity, Ed. Roald Dijkstra, Sanne van Poppel, Danielles Slootjes, 'Measuring the Power of the Roman Empire,' p. 44, Radboud Studies inhumanity Vol 5. 2015; cf. Timothy Barnes who argues that the later Constantinian prefects are more expressions of the emperor's dynastic aims than definitively administrative in character: Constantine: Dynasty, Religion and Power in the Later Roman Empire, 2011, pp. 290-293 ISBN978-1118782750; previously prefects were personal, i.e. attached to the office of the emperor and not territorially defined
Codex Theodosianus 1, 15, 7 (377) shared, not derived from prefects, 「vicaria dignitas ipso nomine se trahere indicet portionem et saepe cognitionis habeat potestatem et iudicationis nostrae soleat repraesentare reverentiam,」 CTh. 1, 15, 7 (377), "the dignity of vicar by its very name indicates that it assumes a part (of the prefecture) that it often has the power if our inquiry and is accustomed to represent the reverence of our judgment;」 Cassiodorus, 「Tu autem vicarius dixeris et tua privigelia non reliquia, quando propria est jurisdictio quae a principe datur. Habes enim cum praefectis aliquam portionem,」 6, 15 - Moreover the you will have been designated vicar and your prerogatives (are) not unchanged, when the jurisdiction which is given by the emperor is his own. For you have with prefects some portion
CAH XII pp. 181-182; Roland Delmaire Les largitiones sacrees et res private, Latomus, 1989, pp. 173, 181, 202-205, 245 ISBN978-272-83061-38; L.E.A. Franks, review of The Judiciary of Diocesan Vicars in the Later Roman Empire, Jacek Wiewiorowski 2016 ISBN978-83-232-2925-4 in Byzantinische Zeitschrift 206 Vol 109 Part 2 pp. 988-994; Jones, LRE pp. 101--102, 414, 434, 448-451- 485-486; M.F. Hendy, Studies in the Byzantine Monetary Economy, 300-1450 A.d., 1985 pp. 373-377 ISBN978-0521088527; from the early 340s inspection of the State Post was placed with master of the offices; maintenance remained with the prefecture; and costs paid for by provincials along the routes
introduction of the procurators by Diocletian, CAH XII, p. 76; Delmaire, disbandment of procurators, p. 206-209 and SL comptroller duties post-325/330 204-205
Jones, pp. 485-486, 1207; Franks, p. 992; CTh. 11, 16, 28 of 359 mentions the transference by Constantine which can tracked to 327–329 by reference to laws 14 and 18
the exceptions were Egypt, which did not have its own vicar till 370 or 380, and in the West according to the Notitia Dignitatum of circa 395, there were 6 vicars, 2 prefects governing dioceses, but 11 comptrollers (two in Africa, two in Pannonia, and one for the Island of Sicilia, Sardinia and Corsica Notitia Dignitatum; Franks, pp. 990-992
Delmaire, op. cit. p 39 from CIL II, 4107 or by 344 at the latest CTh. 8, 2, 10. The heads of the SL and RP were made 'comites' the same year; and Prefect of the Annona of Rome senator also in 326 from Chastognol cited by Rickman, The Corn Supply of Rome, 1980 p. 200, dated the elevation of the prefectus annonae of Rome to senator to the year 326
Southern and Dixon, The Late Roman Army, 1996, pp. 62-63, ISBN0-300-06843-3; R. Mitthof, Annona Militaris: Die Heeresversorgung im spätantiken Aeygpten, (Papyrologica Fiorentiana 32) 2001, pp. 273-286. Mithoff states that civilian control was for security purposes but it was inefficient as it relied on reluctant local officials and liturgists to collect and distribute massive quantities of supplies which could have been more efficiently bought on the open market as required; Justinian reverted to direct purchase. The lack of gold in circulation until the end of the 4th century hindered the transition, Delmaire, pp. 709-712; Jones 207-208, 235, 460-461
Joachim Migl, Die Ordnung der Amter des Pratorianerprafaktur und Vicariat in der Regionsverwaltung des Romischen Reiches von Konstantin bis zur Valentinianischen Dynsatie, 1993. pp. 54-58; Franks, pp. 992-993
Delmaire, pp. 709-711; Jones, pp. 485-486; Franks, p. 992; the laws allowing appeals once again to the counts of the SL and RP with the emperors CTh. 11, 35, 45 = CJ 7, 62 26 to the RP and 46 to the SL both of year 385
The picture is one of occasional interventions from and a permanent awareness of the higher levels of provincial government; the whole bureaucratic machinery seems to have been intended to maximize revenues and channel these according to government policies; including a system of checks and measures to insure accountability, Roger Rees, Diocletian and the Tetrarchy, 2004, p. 35 ISBN0-7486-1661-6; speaking of Egypt, "The imperial administration was therefore present above all in those cities in which the governors had their seats," Egypt in the Byzantine World, 300- 700 AD, Ed. Roger Bagnall, 2007, 'The Imperial Presence: Government and army, pp. 249-251 ISBN978-0521-14587-9, 4 cities in a crowded land, 2,000 officials total for 4.75 million inhabitants
cf. Relationes of Symmachus, urban prefect of Rome 382-384, who passed on cases to get them off his hands, Barrow, R.H., Prefect and Emperor, The Relationes of Symmachus, A.D. 384, Oxford University Press, 1973 Barrow, The Relationes of Symmachus; Jones, pp. 490-491; Wiewiorowski, pp. 291-292
(in the southern part of the Diocese of Italy where the Urban Prefect of Rome also had this authority; from 361 the urban prefect of Constantinople had appellate authority in 9 adjacent provinces in the dioceses of Thrace, Pontus and Asia to match the dignity of the prefect in 'Old' Rome, and of course the praetorian prefect of the East); proconsuls were iudices ordinarii judges of the first instance and vice sacra iudicantes, appellate judges in their own provinces, Jones, p. 481-482; the four prefects of the Annona did not have appellate jurisdiction - if something went amiss cases went to a prefect or vicar, for a complicated multi-jurisdictional case headed by the vicar in Africa CTh. 11, 1, 13 (366)
Franks, pp. 990-991; 'munera' is the plural of 'munus', which in effect was a type of tax; see CTh. 1, 12, 2 (319) of the proconsul of Africa's financial oversight duties which were identical to those of the vicar of Africa
the prefects used the latter in preference from the mid-5th century to communicate directly with their provincial permanent counterparts and ad hoc deputies in the provinces thus bypassing the diocesan department heads, the 'curae epistolarum,' one sign of diocesan decline, Jones, pp. 281
Southern and Dixon, The Late Roman Army, 1996, pp. 62-63, ISBN0-300-06843-3; Jones, pp. 623-630; R. Mitthof, Annona Militaris: Die Heeresversorgung im spätantiken Aeygpten, (Papyrologica Fiorentiana 32) 2001, pp. 273-286
"…the Comes Orientis had special powers and duties in connection with military matters (probably concerning the organization of supplies and the quartering of troops),」 Downey, Glanville, A History of Antioch in Syria, 1963, p. 355. The last comes orientis 335-337 was making preparations for Constantine's invasion of Persian when the emperor died; also the vicar of Britain, the Augustal Prefect (vicar) of Egypt and the vicars of Pannonia and Dacia had important defense responsibilities;
A.H.M. Jones, The Later Roman Empire, 1964 pp. 374, 450, 496, "the vicars seem to have deputized for the praetorian prefects in all their manifold functions,' p. 47; Stephen Williams, Diocletian and the Roman Recovery, 1985, p. 110, "The prefect had ultimate responsibility ...for the whole apparatus of civil administration, including taxation...he was now able to delegate much of the detailed work to the 12 vicars with their attached fiscal departments" ISBN0-416-01151-9
Giardina, Andrea, Aspetti della burocrazia nel basso impero, Edizioni dell』Atneo & Bizzarri, 1977, pp. 45-93, 「the agentes in rebus were part of a widespread system of control. There were various sectors of the government which they operated in as guarantees of political security. These sectors covered all vital nerve tissue bundles (「ganglia」) (or focuses of strength metaphorically) of the State, from the lines of communication to imperial defense factories, from the transmission of messages to the command of the civil service bureaux, to prevent rebellion, to control the administration and apply the laws: there were sore points for the late ancient State, and for this reason, these were subjects of great concern to the central government and, what’s more, if one thinks about it, the reason for the very frequent orders concerning the collective responsibility of government departments. The presence of agentes in rebus, who through long familiarity with administrative functioning, were experts in jobs of varying responsibilities must have guaranteed the efficient carrying out of technical work, administrative surveillance and political control,「 p. 71
Jones, p. 128; A. Piganiol, L』empire chretien (325-395), 1947, p. 321 「lui-meme ne depend pas des prefets du pretoire, mais directemente du prince; le prefet ne peut intercepter ses rapports, et c』est au prince, non pas au prefets, qu’on fait appel des decisions judicaires du vicaire,」 p. 354.
Codex Theodosianus 6, 28 4 (387 = Codex Justinianus 12, 21, 1); Sinnigen, William G. 'Three Administrative Changes attributed to Constantius II', American Journal of Philology, 83, 1962, pp. 369-383
