What caused the expansion of the Vikings as a force that spread fear in Europe? Experts debate how climate change and other factors affected their travels.

In the French Empire, the Vikings face a new kind of defence and Charlemagne, who refuses to give up Christian land to heathens and pirates; the defence holds, but suddenly everything changes.

In the second half of the 900s, the Vikings return to France, but this time they choose unification over robbery.

The Vikings go from plundering monasteries to a power struggle for the throne; The Battle of Hastings 1066 was to mark the end of the Viking Age, but would instead be the beginning of a time of Viking blood on England's throne.