856 - Vikings plunder France

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
Ireland
Olaf the white became the second king of Dublin, he ruled until 871
Thors Hammers from runestones