Centuries: 3rd century - 4th century - 5th century
- September 6 - Battle of Frigidus: The Christian Roman Emperor Theodosius I defeats and kills the pagan usurper Eugenius and his Frankishish general Arbogast.
- The Olympic Games are abandoned by Roman emperor Theodosius I.
- The sacred fire of the Roman Empire stop burning (see Vesta).
- Epiphanius of Salamis attacks Origen as a heretic.