296 St Marcellinus began his reign as Catholic Pope. The violent persecution of Roman Emperor Diocletian dominated his papacy. Also the papal archives were seized and destroyed, but the famous Cemetery of Calixtus was saved by the Christians when they blocked its entrance.
350 Roman usurper Nepotianus, of the Constantine dynasty, was defeated and killed in Rome by troops of the usurper Magnentius.
1397 Denmark, Norway & Sweden signed the Union of Kalmar under Queen Margaretha.