Crisis of the Third Century
PoliticsEconomyThe Roman Empire nearly collapses under civil wars, invasions, plague and economic crisis until Diocletian's accession.
- Date
- 235 – 284 · View on map
- Countries
- Italy
- Importance
- ★★★★★
The Roman Empire nearly collapses under civil wars, invasions, plague and economic crisis until Diocletian's accession.
Ardashir I defeats the last Parthian king, founding the Sasanian Empire, the last Iranian empire before the rise of Islam.
The death of the philosopher-emperor Marcus Aurelius is often regarded as marking the end of the Pax Romana.
Constantine defeats Maxentius near Rome; according to tradition he saw a Christian sign before the battle.
Emperors Constantine and Licinius agree on religious toleration, ending the persecution of Christians in the Roman Empire.
Claudius Ptolemy completes the Almagest, setting out a geocentric model of the cosmos that remains the standard work of astronomy for over a millennium.
The first ecumenical council of Christianity, convened by Constantine, condemns Arianism and formulates the Nicene Creed.