I idled away some travel time yesterday reading sections of King Harald's Saga, available, inter alia, on Kindle from Penguin. There must be a market for such accounts Viking of derring-do: Penguin seems to keep quite a number in print. Myself, I have several weathered paperback editions around the house although I'm not sure I ever actually read any before: always one of those things I would get to next year, after finishing Clarissa for example, or Finnegans Wake (the answers are no, and no).
I suppose I'm sorry I waited. The Saga is a rattling good story, with superb intro material by Magnus Magnusson and Herman Pálsson (on Magnusson's own remarkable career, go here; Pálsson's equally distinctive bio is here). Harald the protagonist has story enough to fill out any self-respecting saga: he saw service in Byzantium and Kievan Rus and died fighting another Harald—rather, Harold—at Stamford Bridge in the North of England in 1066 (the winner went on to lose the Battle of Hastings to William of Normandy, aka William the Conqueror). But in addition to Harald the protagonist, the editors introduce the reader to another, perhaps even more interesting, character: Snorri Sturluson, author of the saga and himself an important player in the tumultuous and violent public life of Scandinavia in his time (Snorri died in his basement at the hands of an assassin: it is said his last words were Eigi skal höggva!—"Do not strike!"). Just off hand, can you think of any other major historian who was both a writer and an active politician? The standard model would seen to be Trotsky or Thucydides, both writing in enforced idleness after their political careers had ended.
But I digress; back to Harald. The really extraordinary fact about this book is the utter absence of anything remotely resembling a “public purpose” in Harald's career (at least not as seen by Snorri). It's all hackin' and hewin', life in tooth and claw, triumph and disaster, betrayal and vengeance.
Which brings me to one reason why it is so interesting to study the Scandinavian record: we can observe, at least dimly and inadequately, the emergence of something you might call “a modern state” (well: states) out of the turbulent stew of what came before. One is necessarily tempted to try to find some quick-and-dirty Twitter-style summary of the transition, and good luck with that. One is tempted, I suppose, to say “the coming of Christianity,” and I suppose there is something to the suggestion though not, perhaps, the way it is commonly understood. It certainly not the case that the Vikings woke up won day and said “Oh! We're Christians! Let's put down our swords and love our neighbors as ourselves!” No: the very process of Christianization was long and painful full of wrong turnings (though not so painful, perhaps, than the transition that led to the 30 Years' War on the Continent, nor the Civil War in England).
But perhaps you can say this much: perhaps what Christianity did do for Scandinavia is to bring on board a fully-developed bureaucratic apparatus with a priestly class, with bishops and archbishops (the Swedes seem even more serious about this sort of thing than the Anglicans). But that's not so much “Christianity” per say as a tradition that extends that right back past the beginning of Christianity to the Roman empire itself. And they do say all roads lead there.