The man who would be king (what a maroon).
Where is the guillotine when you need it the most?
Charles didn't start out this way. But I think the growing realization that he will be an old man by the time his mum passes on (his grandmother lived to 101 and the Queen is healthy as a horse) has combined with decades of life in a media fishbowl to make him barmy in the head, just a bit.
His sister Anne was smarter; she dropped out of sight and stayed that way.