Under the new organization of the empire by Diocletian, Numidia was divided in two provinces: the north became Numidia Cirtensis, with capital at Cirta, while the south, which included the Aurès Mountains and was threatened by raids, became Numidia Militiana, " Military Numidia ", with capital at the legionary base of Lambaesis.

In the early 4th century all Cilicia was detached by order of Diocletian for administrative purposes from the northern slope of Taurus, and we find a province called at first Isauria-Lycaonia, and later Isauria alone, extending up to the limits of Galatia, but not passing Taurus on the south.

In an attempt to save the Empire, Diocletian reorganized the provinces in 293, with the establishment of the Diocesis Viennensis in the south of Gaul, comprising the former Gallia Aquitania and Gallia Narbonensis.

At the end of the third century AD, the Emperor Diocletian divided the great Roman province of Africa Proconsularis into three smaller provinces: Zeugitana in the north, still governed by a proconsul and referred to as Proconsularis, Byzacena, and Tripolitania in the south.

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.

After the reforms of Diocletian in the late 3rd century, Epirus Vetus was split off, and sometime in the 4th century, the province of Macedonia itself was divided into Macedonia Prima in the south and Macedonia Salutaris in the north.

Emperor Diocletian made Dalmatia famous by building a palace for himself a few kilometers south of Salona, in Aspalathos / Spalatum.

Following some public disputes with Manicheans, Diocletian ordered that the leading followers of Mani be burnt alive along with their scriptures.

In Southern's opinion, these reforms and the decline in senatorial influence not only helped Aurelian to salvage the Empire, but they also make Gallienus one of the emperors most responsible for the creation of the dominate, along with Septimius Severus, Diocletian and Constantine I.

* Emperor Diocletian gains several victories along the Danube against the Sarmatians.

Under Diocletian ( 245 – 313 ), Noricum was divided into Noricum ripense (" Noricum along the river ", the northern part southward from the Danube ), and Noricum mediterraneum (" landlocked Noricum ", the southern, more mountainous district ).

Constantius remained in Britannia for a few months, replaced most of Allectus ’ officers, and the British provinces were probably at this time subdivided along the lines of Diocletian ’ s other administrative reforms of the Empire.

Hundreds of years later, under the Emperor Diocletian and his successors, new legions raised for the field armies, as opposed to those stationed along the frontiers, were recruited to only about 1, 000 men and were, therefore, the size of military auxiliary cohorts.

Eugene along with the martyrs Saint Candidus, Valerian and Aquila was persecuted " during the reign of Diocletian ( 284-305 ) and Maximian ( 305-311 )" under the military leader Lycius.

On March 31, 302, in a rescript from Alexandria, Diocletian, after consultation with the proconsul for Egypt, ordered that the leading Manicheans be burnt alive along with their scriptures.

Diocletian dated his reign from his elevation by the army, not the date of his ratification by the Senate, following the practice established by Carus, who had declared the Senate's ratification a useless formality.

The following spring, as Maximian prepared a fleet for an expedition against Carausius, Diocletian returned from the East to meet Maximian.

Diocletian then returned to Sirmium, where he would remain for the following winter and spring.

Diocletian soon grew impatient with the city, as the Romans acted towards him with what Edward Gibbon, following Lactantius, calls " licentious familiarity ".

After the abdication of Diocletian in 305, and the accession in Rome of Maxentius to the throne of the Caesars in October of the following year, the Christians of the capital again enjoyed comparative peace.

Aside from the rank and file legionary ( who received the base wage of 10 asses a day or 225 denarii a year ), the following list describes the system of officers which developed within the legions from the Marian reforms ( 104 BC ) until the military reforms of Diocletian ( c. 290 ).

In addition to establishing the tetrarchy, Diocletian devised the following system of denominations: an aureus struck at the standard of 60 to the pound, a new silver coin struck at the old Neronian standard known as the argenteus, and a new large bronze coin that contained two percent silver.

* The reign of Emperor Diocletian ( 284-305 ), who attempted substantial political and economic reforms, many of which would remain in force in the following centuries.

Diocletian remained in Antioch for the following three years.

In 295 and 296 Diocletian campaigned in the region again, and won a victory over the Carpi in the summer of 296.

* Late summer – Diocletian defends the Danube against Sarmatian raids.

He was a man skilled in areas of government where Diocletian, presumably, had no experience.

They met at the same hill, out of Nicomedia, where Diocletian had been proclaimed emperor.

Diocletian saw his work as that of a restorer, a figure of authority whose duty it was to return the empire to peace, to recreate stability and justice where barbarian hordes had destroyed it.

The term Tetrarchy ( Greek: " leadership of four ") describes any form of government where power is divided among four individuals, but in modern usage usually refers to the system instituted by Roman Emperor Diocletian in 293, marking the end of the Crisis of the Third Century and the recovery of the Roman Empire.

Diocletian may or may not have been present at the battle, but would present himself soon afterwards at Antioch, where the official version of events was made clear: Galerius was to take all the blame for the affair.

Helena and her son were dispatched to the court of Diocletian at Nicomedia, where Constantine grew to be a member of the inner circle.

Theophanes ' chronicle of world events, covering events from the accession of Diocletian in 284 ( the point where the chronicle of George Syncellus ends ) to the downfall of Michael I Rhangabes in 813, is valuable for preserving the accounts of lost authorities on Byzantine history that would be otherwise lost for the seventh and eighth centuries.

In the early Byzantine period ( 4th to early 7th century ) the system of government followed the model established in late Roman times under Diocletian and Constantine the Great, with a strict separation between civil and military offices and a scale of titles corresponding to office, where membership or not in the Senate was the major distinguishing characteristic.

The decree now exists only in fragments found mainly in the eastern part of the empire, where Diocletian ruled.

Under the reign of Western Roman Emperor Maximian, co-emperor with Diocletian, Cyriacus was tortured and put to death, beheaded in 303 on the Via Salaria, where he was subsequently buried.

Early in the persecution of Diocletian the Emperor summoned Chrysogonus to Aquileia where he suffered martyrdom.

On the exhibition, in the Baths of Diocletian at Rome, of Sigalon's gigantic task, in which he had been aided by his pupil Numa Boucoiran, the artist was visited in state by Gregory XVI.

Diocletian, impressed with the boy's determination to resist, promised him wealth and power, but Pancras refused, and finally the emperor ordered him to be decapitated on the Via Aurelia, on May 12, 303 AD ; this traditional year of his martyrdom cannot be squared with the saint's defiance of Diocletian in Rome, which the emperor had not visited since 286, nor with the mention of Cornelius ( 251-253 ) as bishop of Rome at the time of the martyrdom, as the most recent monograph on Pancras's texts and cult has pointed out.

* 286 – Emperor Diocletian elevates his general Maximian to co-emperor with the rank of Augustus and gives him control over the Western regions of the Roman Empire.

Alexander ’ s reign contained some of the last major building works constructed in Rome before the reign of Diocletian.

Although the Principate continued in theory until the reign of Diocletian, Severus Alexander's death signalled the beginning of the chaotic period known as the Crisis of the Third Century which brought the empire to near collapse.

In his Easter table the year 532 AD was equated with the regnal year 248 of Emperor Diocletian.

Ar., lxiv, and De Syn., xviii ), St Athanasius does not recall from memory being a first hand witness to the onset of the great persecution by the Tetrarchy of Diocletian and Maximian in February 303, for in referring to the events of this period he makes no direct appeal to his own personal recollections, but falls back on tradition.

The most usual shabi term for the geographic area of a bishop's authority and ministry, the diocese, began as part of the structure of the Roman Empire under Diocletian.

A further massive transfer of Bastarnae was carried out by emperor Diocletian ( ruled 284-305 ) after he and his colleague Galerius defeated a coalition of Bastarnae and Carpi in 299.

Such numbers may have amounted to a substantial proportion, if not all, of the Peucini Bastarnae: Victor claims that the Carpi resettled in Pannonia by Diocletian at the same time, together with those previously transferred by Aurelian, amounted to the entire Carpi tribe.

Art dating from the Diocletian period ( 286 – 305 AD ) in Villa Romana del Casale, Sicily depicts women in garments resembling bikinis in mosaics on the floor.

Palace of the Roman Emperor Diocletian, around which the Croatian city of Split ( city ) | Split emerged.

Dalmatia was the birthplace of the Roman Emperor Diocletian, who, upon retirement from Emperor in AD 305, built a large palace near Salona, out of which the city of Split later developed.

After the Western Roman Empire collapsed in 476, with the beginning of the Migration Period, Julius Nepos shortly ruled his diminished domain from the Diocletian palace after his 476 flight from Italy.

Also, alone in Europe until the 13th century Italian florin, the Empire continued to produce sound gold coinage, the solidus of Diocletian becoming the bezant prized throughout the Middle Ages.

Diocletian (; c. 22 December 244 – 3 December 311 ), was a Roman Emperor from 284 to 305.

Born to a family of low status in the Roman province of Dalmatia, Diocletian rose through the ranks of the military to become cavalry commander to the Emperor Carus.

After the deaths of Carus and his son Numerian on campaign in Persia, Diocletian was proclaimed Emperor.

The title was also claimed by Carus ' other surviving son, Carinus, but Diocletian defeated him in the Battle of the Margus.

Diocletian delegated further on 1 March 293, appointing Galerius and Constantius as Caesars, junior co-emperors.

Diocletian secured the Empire's borders and purged it of all threats to his power.

Galerius, aided by Diocletian, campaigned successfully against Sassanid Persia, the Empire's traditional enemy.

Diocletian led the subsequent negotiations and achieved a lasting and favorable peace.

Diocletian separated and enlarged the Empire's civil and military services and reorganized the Empire's provincial divisions, establishing the largest and most bureaucratic government in the history of the Empire.

Weakened by illness, Diocletian left the imperial office on 1 May 305, and became the only Roman emperor to voluntarily abdicate the position.

Diocletian was probably born near Salona in Dalmatia ( Solin in modern Croatia ), some time around 244.