it doesn't seem to be that uncommon to have some ancestry that was part of royalty: https://www.bbc.com/news/uk-59041055

Many of us will have shared ancestors. And if someone has ancestry in Britain going back to the Middle Ages, Prof King says it's actually more likely than not they will be related to a branch of one of the royals.

He was also depicted as the villain in the Robin Hood tales.

Feels about right.