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.

During the Tetrarchy ( Emperor Diocletian's reform of Roman governmental structures in 296 ), Mauretania Tingitana became part of the Diocese of Hispaniae, ' the Spains ', and, by extension, part of the Praetorian Prefecture of the Gauls.

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.

Diocletian's Palace near Salona ( today's downtown of the city of Split, Croatia | Split in Croatia )

Rumors alleging that Diocletian's death was merely being kept secret until Galerius could come to assume power spread through the city.

Modern view of Diocletian's Palace near Salona ( in Split ( city ) | Split, Croatia )

The city itself grew around the heavily fortified Diocletian's Palace the Emperor had built in anticipation of his retirement.

He was baptized and instructed in the city, and lived in Palestine in 296, when Diocletian's army passed through the region ( in the Life of Constantine, Eusebius recalls seeing Constantine traveling with the army ).

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.

Near the city emperor Diocletian, born in Salona, built the Diocletian's Palace ( around year 300 AD ), which is the largest and most important monument of late antique architecture in the World.

When the Roman Emperor Diocletian retired, he erected a monumental palace nearby ; this massive structure, known as Diocletian's Palace, became the core of the modern city of Split.

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.

Palace of the Roman Emperor Diocletian, around which the Croatian city of Split ( city ) | Split emerged. Diocletian's Palace viewed from the south. The basement of Diocletian's Palace. Peristyle and the Cathedral of St. Domnius-a tourist attractionThe ground plan of the palace is an irregular rectangle ( approximately 160 meters x 190 meters ) with towers projecting from the western, northern, and eastern facades.

The Jadro River ( the original water supply for the ancient city of Diocletian's Palace ) flows through the town of Solin and provides water supply to both Split and Kaštela.

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.

It has been surmised that the ceremonies were arranged to demonstrate Diocletian's continuing support for his faltering colleague.

In the spring of 293, in either Philippopolis ( Plovdiv, Bulgaria ) or Sirmium, Diocletian would do the same for Galerius, husband to Diocletian's daughter Valeria, and perhaps Diocletian's praetorian prefect.

In preparation for their future roles, Constantine and Maxentius were taken to Diocletian's court in Nicomedia.

Bureaucratic affairs were completed during Diocletian's stay: a census took place, and Alexandria, in punishment for its rebellion, lost the ability to mint independently.

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.

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.

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

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 ).

Painting depicts two Christian women extracting arrows from St. Sebastian, who has been left for dead by the Roman emperor Diocletian's archers ( between 1851 and 1873 ).

In Diocletian's Tetrarchy, the traditional seniorities were maintained: Augustus was reserved for the two senior emperors and Caesar for the two junior emperors-each delegated a share of power and responsibility but each an emperor-in-waiting, should anything befall his senior.

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 ).

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.

By the end of Diocletian's reign in 305, the Edict was for all practical purposes ignored.

Hébrard was involved in several other major projects, such as the upgrading of Casablanca, reconstruction of Diocletian's palace at Split, and planning for several towns in French Indochina.

" As with Diocletian's Edict on Maximum Prices, shortages lead to black markets where prices for the same good exceed those of an uncontrolled market.

Diocletian's palace was an inspiration for Adam's new style of Neoclassical architecture and the publication of measured drawings brought it into the design vocabulary of European architecture for the first time.

Diocletian's elevation of Bassus as consul symbolized his rejection of Carinus ' government in Rome, his refusal to accept second-tier status to any other emperor, and his willingness to continue the long-standing collaboration between the Empire's senatorial and military aristocracies.

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.

* Maxima of Rome, early Christian saint and martyr killed in Emperor Diocletian's purges

He seems not to have served in any important military or administrative position during Diocletian's and his father's reign, though.

In the 6th Century, when Justinian increasingly reversed Diocletian's strict separation of civil and military authority, praeses granted military authority over their province were generally elevated to the related, older term Praetor.

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 ).

In spite of Diocletian's request, local judges often enforced executions during the persecution, as capital punishment was among their discretionary powers.

Following Diocletian's abdication in 305, civil war erupted among the various co-emperors, during which time each of the contenders appointed his own prefect, a pattern carried on during the period where the Empire was shared between Licinius and Constantine I.

At Diocletian's behest, Maximian abdicated on May 1, 305, gave the Augustan office to Constantius, and retired to southern Italy.

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.

According to Lactantius, Galerius had forced Diocletian's hand in the matter, and secured the appointment of loyal friends to the imperial office.