What century should I base my historical fiction on?

I’m writing a fantasy/historical fiction series. It’s going to meld early Middle Ages with a fantasy world. I have a very specific conflict between characters in mind but I also want to make the conflict grounded in historical accuracy. It’s been a while since I studied the time period so I’m a little rusty.

Long story short, a young man falls in love with a woman from another realm. His parents, however, chastise him and condemn the woman and the relationship as pagan. I figured the early Middle Ages would be a good spot for this, as Christianity is being spread to the “barbaric and pagan races” at the time. I know that this would generally be the time when the Church would set down things like Christmas and Easter and All Saint’s Day, in order for the “pagans” to worship Jesus instead of their gods. I’d just like to know more in detail as to when a conflict like this would really occurr in a household. I’m also not sure WHERE to place the main character and his family (i.e. England? Somewhere in mainland Europe?) Their family background is also poor and lowly, so they’re not royal in any way.