May 1 – Emperor Diocletian abdicates at age 60 and retires to his palace at Salona (modern Split) on the Adriatic coast after a reign of nearly 21 years in which the last vestiges of republican government have disappeared.
Jones's best-known work, The Later Roman Empire, 284–602 (1964), is considered the definitive narrative history of late Rome and early Byzantium, beginning with the reign of the Roman tetrarch Diocletian and ending with that of the Byzantine emperor Maurice.
In the Golden Gateway of the palace of Diocletian at Split the discharging arches, semicircular in form, were adopted as architectural features and decorated with mouldings.
Built in 1898 in the Italian Renaissance Revival architectural style from a design by Whitman & Hood, the symmetrical tan brick building features an upper arcade of six Georgian Revival windows, an arched center entrance stoop flanked by multi-paned Diocletian windows, arched wings, and a curved pediment dormer crown sporting the Needham Public Schools seal.
He was also a noted contributor on the issue of Christian persecution between the reigns of the Roman Emperors Trajan and Diocletian.
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).
A trained architect, he carried out numerous projects, including a plan of the Imperial forums in Rome in 1933; the restoration of the northwest portion of the Baths of Diocletian (1927) and also work on the Planetarium of the same complex.
São Gens, a Celtic saint, martyred in Arles na Gália, during the reign of Emperor Diocletian, and over time the locals began to refer to this saint as São Ginês, due to its easy of pronunciation.
San Marino claims to be the oldest constitutional republic in the world, founded on 3 September 301, by Marinus of Rab, a Christian stonemason fleeing the religious persecution of Roman Emperor Diocletian.
Towards the end of the 3rd and during the 4th century, as a result of the orientalizing of the Imperial court by Diocletian, it became customary to celebrate as a matter of course the superhuman virtues and achievements of the reigning emperor, in a formally staged literary event.
Close to Park Crescent lies the site of some Roman burials from the 4th century, identified by coins of Diocletian (reigned 284–305) and Constantine I (reigned 306–337) which were found with them.
The Virgin Martyr, in which Dekker probably had a large share, is really a miracle play, dealing with the martyrdom of Dorothea in the time of Diocletian, and the supernatural element is freely used.
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.
Basilides, Cyrinus, Nabor and Nazarius are saints of the Roman Catholic Church, mentioned in the Martyrology of Bede and earlier editions of the Roman Martyrology for 12 June as four Roman martyrs who suffered death under Diocletian.
Hieromartyr Clement, Bishop of Ancyra or simply Clement of Ancyra (c. 258-312) (born in Ancyra present-day Turkey) was a bishop who served during the rule of Roman emperor Diocletian.
Catholic tradition states that Erasmus of Formiae, also known as Saint Elmo, was finally executed by disembowelment in about A.D. 303, after he had suffered extreme forms of torture during the persecutions of Emperor Diocletian and Maximian.
Eulalia of Mérida was a young Roman Christian martyred in Emerita, the capital of Lusitania (modern Mérida in Spain), conventionally during the persecution under Diocletian and Maximian.
Noteworthy remains are the statue of the god Vertumnus; the Furlo Pass, constructed by the Emperor Vespasian to shorten the passage of that mountain; and the bridge of Trajan (115) near Calmazzo, and that of Diocletian (292), both over the Metaurus.
Galeria Valeria (died 315) was the daughter of Roman Emperor Diocletian and wife of his co-emperor Galerius.
Sossianus Hierocles, 3rd-4th century, proconsul of Bithynia and Alexandria during the reign of Diocletian
Thus Diocletian, who ruled from Nicomedia, promoted two faithful legions from the Illyricum (Legio V Iovia and VI Herculia), the area he was also descended from, to be the personal protectors of the Roman Emperors.
The cognomen of this legion came from Herculius, the attribute of Maximian (Diocletian's colleague) meaning "similar to Hercules".
The cognomen of the legion refers to Hercules, to whom Diocletian's colleague, Maximian (also known as Herculius, "the man like Hercules"), was devoted and identified.
In 305, Diocletian and Maximian abdicated, and the former caesares Constantius and Galerius became Augusti.
Prefecture most commonly refers to a self-governing body or area since the tetrarchy when Emperor Diocletian divided the Roman Empire into four districts (each divided into dioceses, grouped under a Vicarius (a number of Roman provinces, listed under that article), although he maintained two pretorian prefectures as an administrative level above the also surviving dioceses (a few of which were split).
Besides its martyred bishops, Syracuse claims other Christian martyrs, such as St. Benignus and St. Eugarius (204), St. Bassianus (270); and the martyrdom of the deacon Euplus and the virgin St. Lucy under Diocletian are thought to be historical.
Even on the supposition that a St. Firmin, native of Pampeluna, was martyred during the persecution of Diocletian, it is certain that the first bishop known to history is St. Eulogius, who defended the divinity of Christ in the councils held during the middle of the 4th century.
As the persecution of Christians during the reign of Roman Emperor Diocletian began, Bishop Narcissus of Girona (in Spain) sought refuge in Augsburg and lodged with Afra and her mother, Hilaria.
Martyr Benjamin slain at Sinai and Raithu (d. 296), martyred during the reign of Diocletian
one of the martyrs Simplicius, Faustinus and Beatrix, Christian Martyr who died in Rome during the Diocletian persecution (302 or 303)
Saint Sebastian was appointed as a captain of the Praetorian Guard of Roman emperors Diocletian and Maximian and was martyred.
Santa Maria degli Angeli e dei Martiri, a basilica in Rome, created by Michelangelo in the Baths of Diocletian
Bishop Ephrem, killed on 7 March 304 in Tomis (modern Constanţa), was the first known Christian martyr of this region, persecution continuing under the emperors Diocletian, Galerius, Licinius and Julian the Apostate.
Scholars have disputed the nature of that collaboration: it has been suggested that the extant text may be a revision by Massinger of the lost play Diocletian (1594).
Under the administrative reforms of Diocletian (r. 284–305), Thracia's territory was divided into four smaller provinces: Thracia, Haemimontus, Rhodope and Europa.
Shortly before the great persecutions of Diocletian and Maximinus II, he withdrew as a hermit to a mountain about six kilometres from Sarsina which is now named after him (Monte San Vicinio, in the present commune of Mercato Saraceno).
Its passionate glorification of Slavs (in which the book includes Alexander the Great and Aristotle, Diocletian and Jerome) and its strong pathos played a major role in the birth of the pan-Slavic ideology.