The archaeological data compiled over the past thirty years or so in Normandy, in particular in the Seine valley, have helped to clarify our knowledge about the Viking phenomenon. Studies of artefacts, and excavations of settlements, or, more rarely, of funerary complexes have shed light on the remarkable potential of certain sites, such as Rouen, Pîtres and Pont-de-l’Arche, whose historical importance has long been known about, where outstanding discoveries have been made, connected with the earliest Scandinavian installations in Normandy.