Dating the Great Heathen Army

A new paper uses radiocarbon dating to confirm authorship of a mass grave associated with the large Viking armies in late 9th century Britain. There's a more layman-friendly article about it from Popular Archaeology.

Sometimes called the Great Heathen Army, or The Viking Great Army, in fact it was several armies that appear to have linked up or fanned out at the decision of their several leaders. Many of these were the sons of Ragnar Lodbrok, about whom the History Channel has been making its famous series. One of them was not, but was instead Guthrum the Old, who became a Christian after his defeat by Alfred the Great. This is the subject of Chesterton's Ballad of the White Horse. Guthrum, christened Athelstan, went on to found the Danelaw in Northumbria.

Far out to the winding river
The blood ran down for days,
When we put the cross on Guthrum
In the parting of the ways.