Prince Charles' favourite classes were history, geography and French. Prince William's - geography and literature. Prince Harry's - art (unlike his father and brother, he positively loathed history and geography).
Diana was not very academically gifted and her favourite class was music; she became an accomplished pianist. I'm not sure about Kate.
I think it's probably fair to say that the Duchess's favorite subject was Art History, which she read at St Andrews. When she and William returned to St Andrews shortly after their engagement announcement, she chatted with the Head of the School of Art History, according to the British newspapers, and told him that she had saved all her essays. (I know him, but he doesn't talk about his students, so I have to take the newspapers' word for what she said.) William did an A-Level in Art History and started reading it at St Andrews, so it obviously interested him, but he seems to have decided that he didn't enjoy university-level study of the subject and switched to Geography, in which he'd earned a high mark at A-Level.
Harry did seem to like Art best. He has some talent judging by some work that was photographed, though there were suggestions that he was assisted by the Art teacher at Eton. Charles, of course, is a competent amateur artist, though not a remarkably good one.
Diana was not much of a student. Academic subjects did not interest her.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.