When the Normans invaded England, were they invaders of Western Europe or were they on Western Europe's side?

They were Vikings from Scandinavia originally who had conquered northern France, an area today called Normandy. They had a great empire for a while and took over not only England but areas in the Mediterranean Sea like Sicily. England had during the previous centuries been heavily settled by people of the area now called Denmark and northern Germany which is the same ethnic stock that migrated into Norway and Sweden to become the Vikings during the dark ages. This displaced Celts and any remaining aboriginal tribes but it is confusing because the earliest Celtic archaeological sites are in Southern Germany and Austria around Saltzburg and Halstadt so one can call them germans as well. If there is anything to be called "Western Europeans" that had an ancient claim to the area then it is perhaps the Picts. They were last recorded in the area of Scotland and would have been disinterested in the antics of the Normans way down south. Other aboriginal peoples are any tribes related to the Basques. These people resisted imilation due to isolation and the incipient speciation caused by their unique blood type, Rh-, of which 2/3 of Europeans have one gene and about 1/6 of the people in England have both and test as Rh-. What one can say is that the earliest tribes of Western Europe were imilated, first by the Celts and then by Germanic peoples like the Angles, Saxons, and Jutes as well as the later Normans. By the time of the Norman invasion, those who fought against them were indistinguishable ethnically from the invaders. Those who might be called 'real' Western Europeans were isolated in distant backwaters of Europe and would have cared little who won or lost, seeing it all as a family squabble.