Events By Place Roman Empire January 18 — Magnentius's proclaimed emperor by the army in Autun. January — Emperor Constans's killed by Magnentius, an usurper. June 3 — Nepotianus proclaims himself Emperor and enters Rome, leading a group of gladiators. June 30 — Nepotianus's defeated and killed by Marcellinus, a general sent by Magnentius. Asia About this time the Huns begin to invade the Sassanid Empire. The city of Anbar's founded. The Wei-Jie war breaks out i… (More on 350)