The Whipping Boy - Sid Fleischman - Bog

A Prince and a Pauper Jemmy, once a poor boy living on the streets, now lives in a castle. As the whipping boy, he bears the punishment when Prince Brat misbehaves, for it is forbidden to spank, thrash, or whack the heir to the throne. The two boys have nothing in common and even less reason to like one another. But when they find themselves taken hostage after running away, they are left with no choice but to trust each other.