The Viking invasion of Britain in 865 AD is sometimes called the Great Heathen Army, or Great Danish Army or the Great Viking Army. Previous invasions were for loot, but this one led to semi-permanent settlement.

A large force of Danish Vikings attacked Anglo-Saxon England. This army appeared in East Anglia in 865. Unlike earlier Vikings who made brief raids on England, the Great army stayed for many years in an attempt to conquer all of England.