How did incest in medieval royalty, particularly sibling incest, actually end up happening socially speaking? Were they just ordered to do it? Surely it wasn't Targaryen-style romance, right?

by Yazman

I'm wondering how it actually occurred in terms of arranging it, and the social response to it.

Was there just a high ranking family member who would actually order two siblings to have sex to produce a child? Or would the family get together and discuss/plan it out?

Was it something they were being obligated to do, or something they chose to do? How would they have actually felt about doing it? And was it a 'one and done' type of thing where they would have sex to produce a child, then never do it again?

I'd really love to know about the actual social dynamics of how these arrangements happened and how the participants felt. Especially since I'm not really aware of royalty or nobility doing this in my own flaired area.

WelfOnTheShelf

I'm not aware of this happening in my own flaired area either, or in any other medieval time/place...in fact the rules against incest were so strong that you weren't supposed to marry anyone related to you within 7 generations. When it became impossible to find anyone more distantly related, they changed it to 4 generations, but even then it was pretty harsh. You could get away with marrying a cousin if everyone was willing to look the other way, but a sibling? I can't think of any examples...did you have any specific people in mind?