Actually, it's not according to the legal definition -- i.e. the killing of a human being by a sane person, with intent, malice aforethought . . . and with no legal excuse or authority.
Now, one with Christian sensibilities will think it's wrong i.e. it's merciless; the old Norse legacy of trial by ordeal led to bearing false witness; it violated the Golden Rule; it was a judgemental, the casting of the first stone and unnecessary but those who don't believe in a divine good greater than the state can't call it murder.
I heartily recommend that you try to find a copy of "Christian History," Issue 63 (Vol. XVIII, No. 3) from 1999. The entire issue is devoted to "A Severe Salvation: How the Vikings took up the faith."
If you think the conversion of Scandinavia was a bottom-up phenomenon, you're in for a surprise.
What I'm saying is that it was not all command of the king or conversion by sword. There was envy good examples of unsung individuals; distorted examples of not so good individuals; and the inherent disatisfaction of a false religion and a pointless life.
There were many Scandinavians who believed before the kings issued the decrees, and many who didn't afterwards.
Anyway, it the conversion was very good for Scandinavia and very good for the world.
Consider King Olaf Trygvesson:
With his fleet now fortified to 94 ships, he came back to England and joined forces with the Danish king Svein Forkbeard. Together they raided England, "burning villages, laying waste the lands, putting numbers of people to death by fire and sword, without regard to sex, and sweeping off an immense booty." Seizing horses, they rode wildly through many provinces and slaughtered the whole population with savage cruelty, "sparing neither the women nor children of tender age."
This was before he became a Christian. The idea that Christianity somehow encouraged any tendancy he had towards violence is not reasonable.
> one with Christian sensibilities will think it's wrong ...
Too bad history does not bear that out.
> the conversion was very good for Scandinavia and very good for the world.
How so? As you point out, it provided no mitigating influence against murderers like the two Olafs.
> the old Norse legacy of trial by ordeal led to bearing false witness...
And claiming that the Norse were unaware of the law and jury trials is also bearing false witness. Much of our current system of laws comes from the old Norse/Germans, with a direct link back to the pre-Christian Saxon common law.
>> If you think the conversion of Scandinavia was a bottom-up phenomenon, you're in for a surprise.
> What I'm saying is that it was not all command of the king or conversion by sword.
Nobody said it was "all" by the sword. The simple fact is that it's fairly easy to convert polytheists... if someone already believes in a dozen gods, adding one more to the pot ain't that hard. Then it's not that far a jump to take that one new god and make him the only god and the other gods into minor deities or even evil demons.... *especially* when the king tells you to do it.
Once again... not exactly miraculous. The real miracle is that the old religion has survived Christianity and has a number of earnest adherants... and has managed to become officially recognized in Iceland. In fact, the old beliefs never were quite wiped out in the Scandinavian lands; even among the Christians of Iceland, respect for the elves (*not* the Keebler/Santa's little helper type of elves) continues to this day. Misteltoe, the names of the days of the week, the Yule Log and the Christmas Tree continue to make the old ways noticable even today.