You do realize that the Norman French were Vikings right? The area was settled by a massive group of Vikings under Rollo. They became the Normans and from Rollo would eventually come William the Conqueror? These Normans were in no way French.
They spoke French, having adopted it after their conquest of, and settlement in Normandy. French, not Norse, was their court language both in Normandy, and later, after the 1066 conquest, in England.
