In spite of his failures, Diocletian's reforms fundamentally changed the structure of Roman imperial government and helped stabilize the Empire economically and militarily, enabling the Empire to remain essentially intact for another hundred years despite having seemed near the brink of collapse in Diocletian's youth.

Diocletian's reforms in the region, combined with those of Septimus Severus, brought Egyptian administrative practices much closer to Roman standards.

Diocletian's reforms shifted the governors ' main function to that of the presiding official in the lower courts: whereas in the early Empire military and judicial functions were the function of governor, and procurators had supervised taxation ; under the new system vicarii and governors were responsible for justice and taxation, and a new class of duces (" dukes "), acting independently of the civil service, had military command.

Most importantly, Diocletian's tax system and administrative reforms lasted, with some modifications, until the advent of the Muslims in the 630s.

Diocletian's reforms created a strong governmental bureaucracy, reformed taxation, and strengthened the army, which bought the empire time but did not completely resolve the problems it was facing: excessive taxation, a declining birthrate, and pressures on its frontiers amongst others.

Gaining sole reign of the empire, he is also noted for re-establishing a single imperial capital, choosing the site of ancient Byzantium in 330 ( over of the current capitals, which had effectively been changed by Diocletian's reforms to Milan in the West, and Nicomedia in the East ) to build the city soon called Nova Roma ( New Rome ); it was later renamed Constantinople in his honor.

After Diocletian's reforms, the functions of the Prefect embraced a wide sphere ; they were administrative, financial, judicial, and even legislative.

After Diocletian's administrative reforms, it was split into Africa Zeugitana ( which retained the name Africa Proconsularis, as it was governed by a proconsul ) in the north and Africa Byzacena in the south, both of which were part of the Dioecesis Africae.

In 293, as part of Diocletian's reforms, the province of Epiros became known as Epirus Vetus ( including Adrianopolis, Phoiniki, Ogchismos, and Bouthroton as the most northerly major cities, and Akarnania and the islands of Kerkyra, Ithaca, and probably Leukas to the south ).

With Diocletian's reforms, it was split from Moesia as a separate province of " Scythia ", being part of the Diocese of Thrace.

Rather, they now characterize it as a much more subtle, gradual transformation, in which Diocletian's reforms of the Imperial office, while significant, are but one point on a sliding scale.

They are first mentioned in 319, but may date to Diocletian's reforms in the late 3rd century.

The legion moved to Aila ( close to modern Aqaba ), probably during Diocletian's reforms, and is recorded as still camping there at the time of the compilation of the Notitia Dignitatum, in the 390s, when it is reported serving under the Dux Palaestinae.

Emperor Constantine completed Diocletian's reforms and organized the Roman Empire into four pretorian prefectures late in his reign, actually the former territorial circumscriptions of the former four imperial tetrarchs to which each praetorian prefect had acted as chief of staff: the Prefecture of the Gauls, the Prefecture of Italy and Africa, the Prefecture of Illyricum, and the Prefecture of Oriens, with each administrated by an imperially appointed Praetorian prefect.

Since Diocletian's Tetrarchy ( 296 ), it was the major province of a diocese confusingly called Galliae (' the Gaul s '), to which further only the Helvetic, Belgian ( both also Celtic ) and German provinces belonged ; with the dioceses of Viennensis ( the southern provinces of Gaul ), Britanniae ( also Celtic ) and Hispaniae ( the whole Celtiberian peninsula ) this formed the praetorian prefecture also called Galliae, subordinate to the western emperor.

Burlington may also have been influenced in his choice of octagon from the drawings of the Renaissance architect Sebastiano Serlio ( 1475 – 1554 ), or from Roman buildings of antiquity ( for example, Lord Burlington owned Andrea Palladio's drawings of the octagonal mausoleum at Diocletian's Palace at Split in modern Croatia ).

The authorities also constructed the city weather station and two " vidilice ", or " look-out points ", as resting places connected with a long stairway all the way to the Diocletian's Palace, the " Riva " promenade and the rest of the city center.

The coastal city of Split is also the second largest city in Croatia, and is well known for its unique Roman heritage which includes UNESCO-protected Diocletian's Palace.

It also gave access to Diocletian's mausoleum on the east ( now Cathedral of St. Domnius ), and to three temples on the west ( two of which are now lost, the third having become a baptistery, originally being the temple of Jupiter ).

John the Lydian, over two centuries later, reported that Diocletian's army at one point totalled 389, 704 men, plus 45, 562 in the fleets, and numbers may have increased later.

The dissemination of imperial law to the provinces was facilitated under Diocletian's reign, because Diocletian's reform of the Empire's provincial structure meant that there were now a greater number of governors ( praesides ) ruling over smaller regions and smaller populations.

The sharp increase in the number of edicts and rescripts produced under Diocletian's rule has been read as evidence of an ongoing effort to realign the whole Empire on terms dictated by the imperial center.

A number of springs and rivers rise in the Dinaric range, including Jadro Spring noted for having been the source of water for Diocletian's Palace at Split.

The Christian Arnobius, writing during Diocletian's reign, attributes financial concerns to provisioners of pagan services: The augurs, the dream interpreters, the soothsayers, the prophets, and the priestlings, ever vain ... fearing that their own arts be brought to nought, and that they may extort but scanty contributions from the devotees, now few and infrequent, cry aloud, ' The gods are neglected, and in the temples there is now a very thin attendance.

After Diocletian's reform of the provinces, governors were called iudex, or judge.

He served with distinction as a soldier under Emperors Aurelian and Probus, and in 293 at the establishment of the Tetrarchy, was designated Caesar along with Constantius Chlorus, receiving in marriage Diocletian's daughter Valeria ( later known as Galeria Valeria ), and at the same time being entrusted with the care of the Illyrian provinces.

Since emperor Diocletian's Tetrarchy reform ( 293 ), the country was further divided in three provinces, as the small, easternmost region Sitifensis was split off from Mauretania Caesariensis.

From the Emperor Diocletian's tetrarchy ( c. 300 ) they became the administrators of the four Praetorian prefectures, the government level above the ( newly created ) dioceses and ( multiplied ) provinces.

From Diocletian's Tetrarchy reform, the provinces were organized into dioceses each administered by a vicarius.

Constantine's rule, however, validated Diocletian's achievements and the autocratic principle he represented: the borders remained secure, in spite of Constantine's large expenditure of forces during his civil wars ; the bureaucratic transformation of Roman government was completed ; and Constantine took Diocletian's court ceremonies and made them even more extravagant.

Alternatively, a more idiomatic style may develop into an equally prestigious tradition of titles, because of the shining example of the original – thus various styles of Emperors trace back to the Roman Imperator ( strictly speaking a republican military honorific ), the family surname Caesar ( turned into an imperial title since Diocletian's Tetrarchy ).

The Augusti and the Caesars are united for the first time to celebrate the 20th anniversary of Diocletian's accession.

In one document the defeated enemies of Diocletian's campaign in the Syrian desert are described as Saracens.

While no contemporary sources on his life are preserved, later sources and legends claim that he died during the Diocletianic Persecution, which ended with Diocletian's retirement in 305. Januarius is the patron saint of Naples, where the faithful gather three times a year in Naples Cathedral to witness the alleged liquefaction of what is claimed to be a sample of his blood kept in a sealed glass ampoule.

The economy of Brač is based mostly on tourism, but fishing and agriculture ( especially wine and olives ) are very important too, as is its precious white stone which was used in building Diocletian's Palace in Split and the Canadian National Vimy Memorial.

While no contemporary sources on his life are preserved, later sources and legends claim that he died during the Diocletianic Persecution, which ended with Diocletian's retirement in 305.

The Acta of the martyrdom of the bishop Fructuosus and his deacons Augurius and Eulogius document his legend ; they are the earliest Hispanic Acta, " marked by a realistic simplicity which contrasts very favourably with many of the Acta of Diocletian's persecution ".

The extension of the line from the main entrance to the apse shows towards Jerusalem, but as an orthodromic distance curve shows towards the obelisk of the Karnak Temple, from where are the sphinxes in the Diocletian's Palace in Split.

Emperors in the forty years preceding Diocletian's reign had not managed these duties so effectively, and their output in attested rescripts is low.

Although effective while he ruled, Diocletian's Tetrarchic system collapsed after his abdication under the competing dynastic claims of Maxentius and Constantine, sons of Maximian and Constantius respectively.

Alexandria, whose defense was organized under Diocletian's former corrector Aurelius Achilleus, held out until a later date, probably March 298.

The Corpus drew on the codices of Codex Gregorianus | Gregorius and Codex Hermogenianus | Hermogenian, drafted and published under Diocletian's reign.

The most that can be said about built structures under Diocletian's reign is that he rebuilt and strengthened forts at the Upper Rhine frontier ( where he followed the works made under Probus's reign, both along the Lake Constance-Basel as well as along the Rhine – Iller – Danube line ), in Egypt, and on the frontier with Persia.

When later authors described the period, this is what they emphasized: Ammianus has Constantius II admonish Julian for disobedience by appealing to the example in submission set by Diocletian's lesser colleagues ; Julian himself would compare the Diocletianic tetrarchs to a chorus surrounding a leader, speaking in unison under his command.

When the proposed government of universal Christendom by five patriarchal sees ( Rome, Constantinople, Alexandria, Antioch and Jerusalem, known as the pentarchy ), under the auspices of a single universal empire, was formulated in the legislation of Emperor Justinian I ( 527-565 ), especially in his Novella 131, and received formal ecclesiastical sanction at the Council in Trullo ( 692 ), the name " patriarch " became the official one for the Bishops of these sees, and the title " Exarch " remained the proper style of the metropolitans who ruled over the three remaining ( political ) dioceses of Diocletian's division of the Eastern Prefecture, namely the Exarchs of Asia ( at Ephesus ), of Cappadocia and Pontus ( at Caesarea ), and of Thrace ( at Heraclea Sintica ).

The term was first used to refer to the bodyguard of a general during the Republic ; later, a unit of Imperial guards ( temporarily restyled cohors palatina, " Imperial Cohort ", circa 300 AD, under Diocletian's tetrarchy ).

The project was originally commissioned by Maximian upon his return to Rome in the autumn of 298 AD and was continued after his and Diocletian's abdication under Constantius, father of Constantine.

Roman Gallaecia under Diocletian's reorganization, 293 AD