I'm presently nearly done reading (fiction) The Long Ships about this region 1022 years ago. I'm enjoying seeing how cultural attitudes that took root in the transition from a bunch of guys doing whatever they wanted, and everyone can be a king as long as they can murder would-be-murderers well enough, to accepting a (supposed) life of peace as followers of Christ.

It makes me want to understand the subsequent 1000 years of history to see how they became as they are now.