The King's Highway

I read this to my daughter tonight for her bedtime book.  I love the illustrations by Howard Fullmer in his retelling of an old fable.  Here is a summary from Goodreads:

Readers will discover the story of a king who must choose an heir to the throne. The king announces that whoever best travels his highway to the castle will be crowned the new king. But a pile of rubble on the king's highway is blocking passage. Watching the splendid parade of wealthy travelers, a shepherd boy named Michael decides to help and clear a path big enough for all the travelers to pass. In so doing, he uncovers an object that will make him the new ruler of the land.
"I am sorry it is so late, Your Highness," whispered Michael, his voice trembling. "I found this while traveling. No one was left to return it so I have come." Then carefully unwrapping his bundle, he revealed the king's ring for all to see.
Taking the ring in his hand, the wise king looked first at it, then at Michael. "That ring is not mine," he said.
"But it must be yours, Your Majesty," said the boy. "It bears your crest."
"Yes, it does bear the crest of royalty," said the king. "But the ring now belongs to you. I proclaimed that he who best traveled the highway would become the new king. By clearing the road so that all could travel, you showed that it is not fine clothing, fancy horses, or even great wealth that makes a king. It is by serving others that one becomes great."

A great moral and a great story.  Do you have a favorite book like that?  Please share!