Is this a good plot??????????????

It's okay, you should concentrate on making it a bit more interesting and not just focusing on the who with whom. It kinda sounds like a soap opera like that. I also discourage placing it in England. A lot of people would be hung up on the fact that this doesn't take place in actual history. You could either have a fictional country, of have a fictional history where you take the original history of England and branch it off somewhere. Like say that not Henry VIII was king, but maybe someone else, he had another brother or you could even branch off earlier. I do recommend the fiction country though, because then you can make up your own surroundings and nothing is going to seem off. If you want to set in actual Tudor England, you would have to read a lot about the details. Clothes, customs, everyday objects and the like. I do like the ending, that is a high point.