Convinced that one man could not rule the huge, besieged Roman Empire, Diocletian, who took power in 284, appointed Maximian as co-emperor in the west in 286 and in 293 added two junior emperors, Constantius and Galerius, forming a Tetrarchy, a rule of four. Each had his own capital close to the frontier, such as Trier, Milan, Sirmium and Nicomedia. He also reorganised the provinces, the army, taxes and prices. In 305 he abdicated and retired to his palace at Split, the first emperor to do so voluntarily. The system broke down into civil war after his retirement.
Before and after
- from 284 CE to 565 CEDominate
- from 285 CE to 1453Byzantine Empire
- from 285 CE to 476 CEWestern Roman Empire
- 293 CEConstruction of Diocletian's Palace
- 293 CEDiocletian establishes the Tetrarchy
- 3rd centuryOrigins of Mangup
- 303 CEConstruction of Etchmiadzin Cathedral
- 23 February 303 CEThe Great Persecution of Christians begins
- from 304 CE to 439 CESixteen Kingdoms
More in Wars, politics & history
- from 499 BCE to 449 BCEGreco-Persian Wars
- from 431 BCE to 404 BCEPeloponnesian War
- 335 BCEAlexander the Great crosses into Asia
- 217 BCEHannibal destroys the Roman army at Cannae
- from 59 BCE to 51 BCECaesar begins the conquest of Gaul
- 2 September 31 BCEOctavian defeats Antony and Cleopatra at Actium
The era
This moment belongs to the Ancient civilizations (3,200 BCE to 500 CE), writing, cities and empires. You can also browse everything in the 3rd century.