Establishment of the Tetrarchy
Diocletian and his co-emperor Maximian each took a junior emperor (Caesar) — Galerius and Constantius Chlorus — creating the “rule of four” that divided the defence and government of the empire.
- Date
- 1 March 293exact dateDate in the Julian calendar
- Place
- Milan (Mediolanum)today: Milan, Italy · Western and Central Europe
- Participants
- Diocletian, Maximian, Galerius, Constantius Chlorus, Roman Empire
- Threads
- Europe in the Roman age (1st–5th c.)
- Also known as
- Tetrarchy; Rule of four; Тетрархия; Правление четырёх
Diocletian had already made Maximian Augustus in the West in 286. On 1 March 293 two Caesars were added: Constantius, invested by Maximian at Milan, and Galerius in the East. Each of the four had his own army and court — at Nicomedia, Sirmium, Milan and Trier — while Diocletian remained the senior partner. Sweeping reforms went with the Tetrarchy: the provinces were split into smaller units grouped into dioceses, the army was reorganized, and taxation, coinage and prices were regulated.
The system worked while Diocletian ruled. After he and Maximian abdicated on 1 May 305 it quickly broke down: in 306 Constantine was proclaimed emperor by his father’s troops at York, and civil wars followed until he became sole ruler in 324.
Connections
Causes and preconditions
- Crisis of the Third CenturyMarch 235 – 20 November 284 · Western and Central Europe
Consequences
- Battle of the Milvian Bridge28 October 312 · Western and Central Europethe break-up of the Tetrarchy led to war among its heirs
Same participants
- Aurelian Walls271–275 · Western and Central Europevia Roman Empire
- Great Persecution24 February 303 – 313 · Balkans and Anatoliavia Diocletian
Same place
- Edict of MilanFebruary 313 · Western and Central Europe
- Division of the Roman Empire17 January 395 · Western and Central Europe
- Siege of Pavia and fall of the Lombard kingdomSeptember 773 – June 774 · Western and Central Europe
- Leonardo da Vinci’s Last Supperc. 1495 – 1498 · Western and Central Europe
- Voltaic pile20 March 1800 · Western and Central Europe
Meanwhile in the world
Other regions, within 25 years of this event
Eastern Europe
- Kyiv culturec. 200 – between 400 and 430
- Chernyakhov culturebetween 200 and 250 – between 400 and 430
Balkans and Anatolia
- Great Persecution24 February 303 – 313
The same period
Sources
- Wikipedia (English): Tetrarchy
- Wikipedia (Russian): Тетрархия
- Williams S. Diocletian and the Roman Recovery. — London: Batsford, 1985.
- Wikidata: Q174450