I've had a random idea floating around in my head recently, and I decided I would take it to Alt. Hist. since, despite my obsession with all matters historical, I still find myself to be quite unknowledgeable in most things pre-dating the 18th century.
So my question: would it be possible, at any point from the fall of the Western Roman Empire on, for Eastern Orthodox Christianity to spread to Scandinavia and either become the dominant religion or an important minority? Or is this just totally ASB with no realistic chance of happening?
Also, one other random question: what would the Old Norse equivalent to the title of Caesar be?