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

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.

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

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

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

It was all good publicity for Diocletian, and it aided in his portrayal of Carinus as a cruel and oppressive tyrant.

As leader of the united East, Diocletian was clearly the greater threat.

It was too much for a single person to control, and Diocletian needed a lieutenant.

Diocletian was in a less comfortable position than most of his predecessors, as he had a daughter, Valeria, but no sons.

The relationship between Diocletian and Maximian was quickly couched in religious terms.

Diocletian refused and fought a battle with them, but was unable to secure a complete victory.

Bahram II's gifts were widely recognized as symbolic of a victory in the ongoing conflict with Persia ; Diocletian was hailed as the " founder of eternal peace ".

Maximian's appointment is unusual in that it was impossible for Diocletian to have been present to witness the event.

It has even been suggested that Maximian usurped the title, and was only later recognized by Diocletian in hopes of avoiding civil war.

On his return to the East, Diocletian managed what was probably another rapid campaign against the resurgent Sarmatians.

Afterwards, during 299 and 302, as Diocletian was then residing in the East, it was Galerius ' turn to campaign victoriously on the Danube.

In a public ceremony at Antioch, the official version of events was clear: Galerius was responsible for the defeat ; Diocletian was not.

It is unclear if Diocletian was present to assist the campaign ; he might have returned to Egypt or Syria.

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

Rhetorically Eusebius records the Oracle as saying " The just on Earth ..." These impious, Diocletian was informed by members of the court, could only refer to the Christians of the Empire.

Diocletian, by contrast, was prodigious in his affairs: there are around 1, 200 rescripts in his name still surviving, and these probably represent only a small portion of the total issue.

Diocletian and the Tetrarchs had no consistent plan for frontier advancement, and records of raids and forts built across the frontier are likely to indicate only temporary claims.

Afterward, the persecutions under Diocletian and Galerius directed his attention to the martyrs of his own time and the past, and this led him to the history of the whole Church and finally to the history of the world, which, to him, was only a preparation for ecclesiastical history.

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.

He was succeeded by Maximinus Thrax, the first of a series of weak emperors, each ruling on average only 2 to 3 years, that ended fifty years later with the Emperor Diocletian ordered split between the Eastern and Western Roman Empires.

By the time of Diocletian, emperors were openly " monarchs ", but the contrast with " kings " was maintained: Although the imperial succession was, de facto, generally hereditary, it was only hereditary if there was a suitable candidate acceptable to the army and the bureaucracy so the principle of automatic inheritance was not adopted.

Whereas before emperors had worn only a purple toga ( toga purpura ) and been greeted with deference, Diocletian wore jewelled robes and shoes, and required those who greeted him to kneel ( proskynesis ) and kiss the hem of his robe ( adoratio ).

Before Christianity became the official religion of the Roman Empire during the reign of the Emperor Constantine I, Diocletian and Maximian passed strict anti-polygamy laws in 285 that mandated monogamy was the only form of legal marital configuration, as had traditionally been the case in classical Greece and Rome themselves.

In this period, from 211 to the accession of Diocletian and the establishment of the Tetrarchy in 286, Rome saw 28 emperors of whom only two had a natural death ( from the plague ).

It was only under Diocletian later in the 3rd-century that these boulai and their officers acquired important administrative responsibilities for their nomes.

The only facts that seem to be certain concern the day, April 19, and the place, Melitene ( now Malatya, Turkey ), of his death ; nothing can be said about the circumstances or the period of his martyrdom ( it has been said that he died under Diocletian, but this is not substantiated.

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

About Januarius, the account says only that he was " bishop as well as martyr, an illustrious member of the Neapolitan church " The Acta Bononensia says that " At Pozzuoli in Campania honored the memory of the holy martyrs Januarius, Bishop of Beneventum, Festus his deacon, and Desiderius lector, together with Sossius deacon of the church of Misenum, Proculus, deacon of Pozzuoli, Eutyches and Acutius, who after chains and imprisonment were beheaded under the Emperor Diocletian ".

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.

Whereas before Emperors had worn only a purple toga and were greeted with deference, Diocletian wore jewelled robes and shoes, and required those who greeted him to kneel and kiss the hem of his robe.

As Morris points out, Diocletian reigned only in the East, and would not have been involved in British affairs in 304 ; Severus, however, was in Britain from 208 to 211.

These " just ", Diocletian was informed by members of the court, could only refer to the Christians of the empire.

Most officials who had served under Carinus, however, retained their offices under Diocletian.

In an act the epitomator Aurelius Victor denotes as unusual act of clementia, Diocletian did not kill or depose Carinus ' traitorous praetorian prefect and consul Ti.

* Summer – Battle of the Margus: Emperor Diocletian defeats the forces of Carinus in the valley of the Margus ( Serbia ).

It has been conjectured that he switched allegiances to support the claims of the future emperor Diocletian just before Diocletian defeated Carinus, the son of Carus, at the Battle of the Margus in July 285.

Maximian's swift appointment by Diocletian as Caesar is taken by the writer Stephen Williams and historian Timothy Barnes to mean that the two men were longterm allies, that their respective roles were pre-agreed and that Maximian had probably supported Diocletian during his campaign against Carinus ( r. 283 – 285 ) but there is no direct evidence for this.

Carinus at once left Rome and set out for the East to meet Diocletian.

In another account, the battle is represented as having resulted in a complete victory for Diocletian, for Carinus ' army deserted him.

This second account is also confirmed by the fact that Diocletian kept Carinus ' Praetorian Guard commander, Titus Claudius Aurelius Aristobulus, in service.

Diocletian proclaimed emperor and marches against Carinus.

* 285 – Carinus dies in battle against Diocletian.