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Birthdate: Diocletian was born on December 22, but his year of birth is disputed. He was probably born around 245 CE. 

(Aurelius Victor, Epitome de Caesaribus, 39) (P. Panop. Beatty 2 Z. 161 – 167)

Birthplace: Diocletian was born in the province of Dalmatia, most likely in the city of Salona (modern-day Solin, Croatia).

(Aurelius Victor, Epitome de Caesaribus, 39) (Zonaras, Extracts of History, 12.32)

Reign: Diocletian was declared emperor by the legions in Nicomedia in 284 CE, following the assassination of his predecessor Numerian. In 305 CE, after ruling the empire for over twenty years, Diocletian abdicated the position of emperor and retired to his palace in Split. 

(Historia Augusta, Lives of Carus, Carinus and Numerian, 12-13) (Zonaras, Extracts of History, 12.30 & 12.32)



(Lactantius, On the Deaths of the Persecutors, 15)


Galeria Valeria (daughter by Prisca)

(Lactantius, On the Deaths of the Persecutors, 15) (Zonaras, Extracts of History, 12.31) (RIC VI Siscia 196)

Death: Diocletian died of natural causes at his palace in Split. Sources agree that Diocletian died on December 3, but his year of death is disputed. He most likely died around 312 CE. 

(Descriptio Consulum) (Aurelius Victor, Epitome de Caesaribus, 39)

Reenactors of Emperor Diocletian and his wife Prisca, Diocletian’s Palace, Split, Croatia, June 2015
Aureus of Diocletian, Palazzo Massimo alle Terme, Rome, December 2018.

Famous facts and dates

In 293 CE, Diocletian established the Tetrarchy. Under this system, the empire was divided into four parts and was ruled by two senior and two junior emperors.
(Zonaras, Extracts of History, 12.31) (Eutropius, Short History of the Roman Empire, 9.22) 
Under Diocletian, the empire experienced high inflation. In 301 CE, in an effort to slow rising prices, Diocletian issued the Edict on Maximum Prices. This decree capped prices on thousands of goods and services, but failed to stabilize the Roman economy.
Diocletian presided over the longest and most severe persecution of Christians in Rome's history. Starting in 303 CE, churches were burned and clergy were imprisoned and executed throughout the empire. This Great Persecution lasted for ten years, finally ending in 313 CE with the Edict of Milan.
(Lactantius, On the Deaths of the Persecutors, 12 & 15) (Eusebius, Ecclesiastical History, 8.2)
In 305 CE, Diocletian became the first Roman emperor to abdicate. He also declined multiple requests to come out of retirement, telling his colleagues that he preferred staying at home and growing cabbages to being emperor.
(Aurelius Victor, Epitome de Caesaribus, 39)
Diocletian helped stabilize the Roman world, and his reign marks the end of the Crisis of the Third Century - a fifty year period when the empire nearly collapsed under internal and external pressures. During his twenty years as emperor, Diocletian crushed multiple internal revolts and barbarian invasions, and he defeated the forces of the Sasanian Empire.
(Eutropius, Short History of the Roman Empire, 9.23 & 9.25)


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Cite this page as: Darius Arya, The American Institute for Roman Culture, “Diocletian” Ancient Rome Live. Last modified 01/14/2024.


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