I am currently reading the 5th Elephant, and fell upon this quote that seems relevant to this question :

[quote:a2b2c4cff1="The Marthter"]Sometimes it seemed to Vimes that everyone knew Carrot was the true heir to the redundant throne of the city. It just so happened that he didn't want to be. He wanted to be a copper, and everyone went along with the idea. But kingship was a bit like a grand piano - you could put a cover over it, but you could still see what shape it was underneath.

[i:a2b2c4cff1](T5E - hard cover page 60)[/i:a2b2c4cff1][/quote:a2b2c4cff1]