Roman emperor Julian is killed during the retreat from the Sasanian Empire.

Julian was the Caesar of the West from 355 to 360 and Roman emperor from 361 to 363, as well as a notable philosopher and author in Greek. His rejection of Christianity, and his promotion of Neoplatonic Hellenism and religious tolerance in its place, caused him to be remembered as Julian the Apostate in the Christian tradition.

The Sasanian Empire, officially Eranshahr, was an Iranian empire that was founded and ruled by the House of Sasan from 224 to 651. Enduring for over four centuries, the length of the Sasanian dynasty's reign over ancient Iran was second only to the directly preceding Arsacid dynasty of Parthia.