May 29 — Battle of Ctesiphon: Julian arrives under the walls of the Sassanid capital and defeats the Sassanid army of Shapur II of Persia, but is unable to put the city under siege.
June 16 — The Roman army starts its retreat from the Sassanid Empire, suffering attacks from the Sassanid forces.
June 26 — Julian is killed in battle. Jovian, a general, is proclaimed Emperor by the troops on the battlefield.
The Council of Laodicea, which deals with constricting the conduct of church members, is held. The major canon approved by this council is Canon 29, which prohibits resting on the Sabbath (Saturday), restricting Christians to honoring the Lord on Sunday.