451
* April 7 - The Huns sack Metz.
* June 20 - The Huns and the Ostrogoths facing the Romans and the Visigoths achieve at best a draw in the Battle of Chalons. After the battle, between 10,000 and 20,000 men lie dead on the Catalaunian Fields.
* In Italy, refugees flee to swamp areas near modern-day Venice.