Yeah, historically it may certainly be used for Viking factions. For example, take what happened when Knut the Great unified most of England, Denmark and Norway, and parts of Sweden during 1014 onward. Also, Sweyn I Forkbeard from 985 onward (England, parts of Norway and Denmark), Harald Bluetooth (Norway and Denmark 958 onward) and so on... history shows examples aplenty about the ambition of different nordic rulers to unite skandinavia and england into one political entity.
The thing is about the triggers. :hmmm: Killing all family members of the rival viking faction may be good.
PS: Thank god I used the searcher, else I would have posted yet another already suggested idea