Some fragment answers: 1. Beginning with Alfred the great, the English were largely able to repel Viking raiders. 2. In the Frankish empire, the Normans and other coastal groups were largely able to repel Viking raiders. 3. By the 11th century, Christianity had strongly taken root in Scandinavia. That was bound to change the way Scandinavians behaved towards fellow Christians in the lands they used to raid. Also around that time, Christian Europeans (especially the fighting types, Scandinavians included) started to turn their attention towards crusading in the middle east. 4. By the 11th century, Scandinavians emigrants were more interested in settling than in raiding. At the same time, large kingdoms such as Norway and Sweden had coalesced. The monarchs up there had to rein in the activities of rogue bands of marauders, lest it escalate into a big old war.