Well, let's go over the information you gave. You said your grandmother's grandmother told her. Okay -- first off what are the ages of you, your grandmother and how old was your grandmother when she was told the story? This would help set up a time frame. When you say "bloody mess" are you referring to the French Revolution? That would narrow it down some more. Now, was this your paternal grandmother or maternal grandmother? That would give some indication as to a last name. If this "prince" was truly disowned and truly a prince, he might have had to change his name or even been forced to change his name. Yes, there could be more than one noble who was disowned. That is why even a last name or a time frame would be helpful. I am not sure how you expect someone to have an answer on what little info. you provided. I only asked because with a little more info. I might have been able to help. The best and only way you are going to prove you were descended from this person is to start with yourself and go backwards. Just because there might be a prince who was disowned and fled France does not mean you are related. You need to sit down and start a family tree. Put yourself first, then your parents, and then your parents parents, and go on from there. Also, read some history books. That is one thing about royals, there are reference guides to many of them. Good luck. I hope it works out for you.