People always ask authors where they get their ideas.
Usually it's impossible to say. I, however, get mine from the people and events of the past. If you'd like to follow up on where my ideas come from feel free to read the bibliography I have collected for my own writing. It will be updated for each new book, so feel free to stop back periodically. We were all given a lot of information about the centuries we call medieval and most of it was made up in later periods to justify various social and religious changes.