OP. Arthur Tudor, whose story was probably much sadder than was previously thought. My thoughts. That sounds very interesting. I have never read your novels although, of course, I have heard of them. Arthur is one of those lost princes, such as the Black Prince or Prince Henry Stuart, that one wonders how history would have changed had he survived.
Mary of Guise was Queen of Scots from 1538 to 1542 as the second wife of King James V. She was the mother of Mary, Queen of Scots, and served as Regent of Scotland in her daughter's name from 1554 to 1560.