364

By place

Roman Empire

• February 17 - Emperor Jovian dies after a reign of eight months. He is found dead in his tent at Tyana en route back to Constantinople, in suspicious circumstances.
• February 26 - Valentinian I is proclaimed Emperor by officers of the Roman army at Nicaea in Bithynia. He addresses the soldiers in a speech. He founds the Valentinian Dynasty and rules the Western Roman Empire, from Caledonia to the Rhine frontier, ensuring it a few years of relative security. He settles in Paris and establishes a militia to defend the region.
• March 28 - Valens, brother of Valentinian I, is appointed co-emperor in the palace of Hebdomon. He rules the Eastern Roman Empire, from the Danube to the Persian border, and begins the first anti-pagan persecutions.
• Britain is forced to endure fierce barbarian raids.

  By topic

Religion

• The Council of Laodicea decides some disciplinary questions of the church and attempts to establish the Biblical canon, but fails.

  Science

• Theon of Alexandria, Greek mathematician, observes a solar eclipse and a lunar eclipse. He gains some renown for his version of Euclid's Elements and his commentaries on Ptolemy's Almagest.