The Black Death in Norway
The population of Norway was at least halved during the Plague. Some figures put the death toll as high as 70%. Nearly the entire clergy was wiped out; only one bishop survived. Old Norse died out because there were so few people left who knew how to speak it. And Norway was so weakened politically by deaths among the nobility that it was forced into a union with Sweden and Denmark, after which it remained under the Danish crown for 400 years.
According to Norwegian folklore, the Plague was an old woman who went from farm to farm. Where she used the rake, some survived; but where she used the broom, everybody died.