That's a pretty big exception you are trying to make. Anyway, Christianity does not provide any ability for kings to rule as "voice of the gods". Further, -- unlike shamanism -- it limits the ability of priests to intrepret the will of God due to a written code. Seeking signs is expressly forbidden.
Norse religion, OTOH, is and arbitrary and filled with superstition. Human sacrfice seems to have been common.
And, the Norse gods are pretty closely identified with totalitarianism.
Plus, if you see a growing power base for that religion surrounding you... well, hop on the bandwagon.
So, it was from the bottom up?
The scientific discoveries of the Greeks were largely lost in the west after Christianization,
They were lost after the fall of Rome, almost 500 years after the arrival of Christianity.
> Christianity does not provide any ability for kings to rule as "voice of the gods".
"Divine right of kings."
Look it up.
> Norse religion, OTOH, is and arbitrary and filled with superstition. Human sacrfice seems to have been common.
Yes, as with many other religions, like Christianity. Before you go all ballistic, imagine how burning a witch looks to non-Christians. Looks a hell of a lot like a human sacrifice.
> So, it was from the bottom up?
By Charlemagnes time? Nope. Top-down, by the link *you* yourself provided. Were it bottom-up, he'd hardly have to fight wars of aggression to force his neighbors to convert. Christianity was the religion of the rulers by this point... the "Old Ways" survived for centuries more among the peasant classes.