What was the impact of the raids of migratory people, such as the Vikings, Magyars, Muslims, etc?

the impact of the raids of migratory people, such as the Vikings, Magyars, Muslims, etc was various, in short term it was mroe or less destructive but for exemple Norsemen were fully incorpporated into Western Civilization same with Magyars who founded Hungary, Muslims after brutal conquest started to use achivments of classic civilization which was cultivated in byzantium and in the latin west in Spain