Events

• Diophantus writes Arithmetica the first systematic treatise on algebra.
• A group of Franks penetrate as far as Tarragona in Spain (approximate date).
• Goths invade Moesia.
• The Alamanni drive the Romans from the modern area of Donau-Ries.
• Decius begins a period of persecution of the Christians in the Roman Empire.

Births

• Maximian, Roman emperor (approximate date)
• Constantius Chlorus, Roman emperor and father of Constantine the Great (approximate date)
• Licinius, Roman emperor (approximate date)
• Arius, Christian priest and namesake of Arianism

Deaths

• January 20 - Pope Fabian
• Ambrose of Alexandria, Christian writer (approximate date)
• Denis, Christian saint
• Saint Alban, Christian saint