The setting I originally chose for my story is proving increasingly difficult to research the history of the land as much was obliterated with the Christianisation of the region. In an effort to be realistic, I find that I am at a stale mate in spite of looking for information for about a year. I've been to libraries, used Google, e-mailed those who are considered experts on the region and received little to no results. My thoughts are to simply create my own world. In some respects this would be easier, but I don't want to delve into the magical. I wanted to focus on the transition to Christianity (as it creates a beautifully tragic conflict for my characters) but I suppose this could simply be the introduction of any new deity at this point. However, again, I don't really want fantasy with magic and elves and spells and creepy ghouls coming from the depths. Is it possible to make a realistic kingdom that doesn't exist without jumping full force into the fantasy genre? I'm anxious to get writing, but I may need to take serious artistic license in order to make my original setting work at this point.
Now I am trying to guess what this place is... you've got me curious! You can always base your world off it as rigidly as possible and then change the name of it, but allude to it in several different ways throughout the book. You could then use your own research, logic, and imagination to estimate what happened and fill in the gaps. By vaguely referencing it people might be able to guess what your world is based on, but couldn't hold you accountable for making historical inaccuracies. Several authors have done it before - like in Hard Times by Dickens. He calls the town Coketown but it it is actually based off of the town of Preston during the Industrial Revolution. Hope you find a solution.
I was planning on using a region of the Basque Lands, but there is so little research on the pre-christian paganism that I fear I will end up imagining all aspects of that pagan culture anyway, only to find out later I was horrifically wrong in my assumptions.
My historian friend is planning a historical novel about the transition between Arianism and the concept of the Trinity. He studies paganism in the Anglo-Saxon era or something - either way he's studying Old Norse and Old English as part of his PhD. Something very old I could ask him a few questions if you PM me them - he might know?