The Prince and the Pauper

 The Prince and the Pauper by Mark Twain

Two boys, one a prince and one a pauper, discover they look alike, almost identical in fact, and so, wouldn't it be fun to change places for awhile? The prince exchanges his rich clothing for the rags of the pauper and heads out into the the streets of London; the pauper dresses himself in the prince's finery and heads into the palace. 

The prince is soon discovered by the pauper's abusive father who mistakes him for  his own son and treats him accordingly. He runs away, is caught again, then is rescued by a kind man who plays along with his claiming to be a prince but in truth thinks he's lost his mind. Again he falls into the hands of his father and his cohorts, is roughly handled, half-starved and tormented, not at all the fun adventure he'd expected when switching identities with the pauper. 

The pauper, who palace officials suspect has lost his mind, doesn't know how to behave, where to go or what to say and doesn't recognize any of the prince's closest advisors and attendants. No one questions him in spite of his strange behaviour because he is, after all, the prince and could order their heads removed at any time. He quickly adapts to living like a prince, enjoying the luxury, the obedience of others whenever he speaks, and the public adulation, even doing some good in the making of more merciful laws for the people. As the time for his coronation as king approaches, his mother recognizes and approaches her missing and much grieved son, but he casts her off. Then, haunted by the pain and sadness in her eyes, he is filled with grief and shame at what he has become. 

In the end the real prince, now the king, is restored to his exalted position, and the pauper is honored and rewarded for the good things he did while the throne was his. Relationships are restored, the good are happy and the bad are miserable -  the right and proper conclusion for any fairytale.