Year 407 (CDVII) was a common year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Honorius and Theodosius (or, less frequently, year 1160 Ab urbe condita). The denomination 407 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

• Gratian, Roman usurper, is installed as emperor after the death of Marcus. According to Orosius, he is a native Briton of the urban aristocracy.
• Gratian is assassinated^[1] and Constantine III, a general (magister militum), declares himself Roman emperor. To extend his dominion over Gaul and Spain, he takes practically all the Roman garrisons from Britain and crosses the English Channel. Constantine occupies Arles and establishes tenuous authority over Gaul, sharing control with marauding "barbarians". This is generally seen as the beginning of Rome's withdrawal from Britain.
• End of Roman rule in Britain: After 360 years of occupation, the local regional British-Roman leaders raise their own levies for defence against Saxon sea rovers. They cultivate oysters, having learned the technique from the Romans.

• Liu Bobo (Xia Wuliedi) founds the state of Xia, and claims the title "Heavenly Prince" (Tian Wang).

• Wen Di, Chinese emperor of the Liu Song dynasty (d. 453)

• Fu Xunying, empress of the Xianbei state Later Yan
• Gratian, Roman usurper
• John Chrysostom, archbishop of Constantinople
• Marcus, Roman usurper
• Maria, empress consort and wife of Honorius
• Murong Xi, emperor of the Xianbei state Later Yan (b. 385)
• Victricius, missionary and bishop of Rouen (approximate date)