The Princess and the Pea by Isadora
Published by Puffin US 2009
When a prince sets out to find a princess to marry, he soon discovers this is not a simple task. There is no shortage of so-called princesses, but how can he tell whether or not they are what they claim to be? Then one night a great storm rages, there comes a knock on the palace gate - and the prince's life is never the same again.