It's believed that Prince Charles won't use his Christian name when he becomes king, but will use one of the other names he has.
So that leaves him with Phillip, Arthur and George.
There has never been a British King Phillip and I don't think he will have that name.
The one and only King Arthur was a mythical warrior king imbued with great strength and powers. I don't think you could get more removed from this big eared, red faced, bumbling buffoon.
So my money is on him being King George V11.