455

By place

Roman Empire

• March 16 - Emperor Valentinian III, age 35, is assassinated by two Hunnic retainers of the late Flavius Aetius, while training with the bow on the Campus Martius, ending the Theodosian dynasty. His primicerius sacri cubiculi, Heraclius, is also murdered.
• March 17 - Petronius Maximus, former domesticus of Aetius, becomes emperor of the Western Roman Empire. He secures the throne by bribing officials of the imperial palace. Maximus consolidates his power by a forced marriage with Licinia Eudoxia, widow of Valentinian III.
• Maximus appoints Avitus, most trusted general, to the rank of magister militum and sends him on an embassy to Toulouse, to gain the support of the Visigoths. He elevates his son Palladius to Caesar and has him marry Eudocia, eldest daughter of Valentinian III.
• May 31 - Maximus is stoned to death by an angry mob while fleeing Rome. A widespread panic occurs when many citizens hear the news that the Vandals are plundering the Italian mainland.
• June 2 - Sack of Rome: King Genseric leads the Vandals into Rome, after he has promised Pope Leo I not to burn and plunder the city. Genseric sacks the city for a period of two weeks. Eudoxia and her daughters, Eudocia and Placidia, are taken hostage. The loot is sent to the harbour of Ostia and loaded into ships, from whence the Vandals depart and return to Carthage.
• July 9 - Avitus is proclaimed Roman emperor at Toulouse, and later recognised by the Gallic chiefs in Viernum.
• September 21 - Avitus enters Rome with a Gallic army. He restores the imperial authority in Noricum and leaves a Gothic force under Remistus, Visigoth general, at Ravenna.
• The Ostrogoths conquer Pannonia and Dalmatia.

Britannia

• Battle of Aylesford: At a place named Agaelesthrep, Hengist fight the native Britons. His brother Horsa is killed and his son Oisc takes his place. According to the account preserved in Nennius, they were opposed by Vortimer.

Asia

• Skandagupta succeeds Kumaragupta I as ruler of the Gupta Empire. During his reign he crushes the Hun invasion; however, the expense of the wars drains the empire's resources and contributes to its decline.
• Gaero becomes king of the Korean kingdom of Baekje.

Mesoamerica

• Earliest recorded date at Chichen Itza on the Yucatán Peninsula .

By topic

Commerce

• Barter economy replaces organized trade as Romans and other citizens desert their towns for the countryside, where they will be less vulnerable to barbarian raids.

Medicine

• The city of Vindobona is struck by an epidemic that spreads through the Roman provinces. The disease is probably streptococcus or a form of scarlet fever with streptococcus pneumoniae.