856 - Vikings plunder France

From Jeufosse by the Seine river  Bjorn Ironside and his vikings ruled with fire and sword, Orleans(18 april), Paris(Burned 28 December) and  and Rouen was attacked and the Eure area was plundered. Later the vikings received fresh reinforcements probably from England.
Vikings established a fortified camp in the island Oscellus (Oissel or Jeufosse) for six years.
Charles the bald gave Maine to Erispoe, duke of Brittany in return for an alliance against Vikings
Olaf the white became the second king of Dublin, he ruled until 871
Thors Hammers from runestones
Considering the time needed to collect a large ransom and the distance of Pamplona from the coast, we can assume that the Vikings must have been in northern Spain for much of the summer of 858.