Once upon a time in a land far, far away, lived a young prince. The prince wanted to get married and searched for the right princess in every kingdom, all over the world. He met many princesses along the way, but there was something not quite right with each of them. They were either too short or too tall, too fat or too thin, too ugly or too pretty. How could he be sure that they were real princesses?

One stormy night there was a knock at the gate. The old king went to answer it. Outside in the rain stood a princess, though she did not look like one at all. The wind had blown her clothes and hair about. Dripping wet with rain, she was a soggy mess. And yet, she claimed to be a princess.

How could they be sure that she was a real princess? The queen had an idea for how to find out. She ordered her servants to prepare a room for the so-called princess. Inside the room, the queen set up a special bed. She stacked up 40 of the very best mattresses, one on top of the other. Underneath the very bottom mattress, the queen placed a single pea. “If she feels that pea, we’ll know she is a real princess,” the queen explained to the prince.

In the morning, the princess left her room and went to see the queen.

“How did you sleep?” the queen asked the princess. “I did not sleep at all,” complained the princess. “I tossed and turned all night—something hard in the bed was poking me all night. It made me black and blue all over.”

The queen was delighted that her test worked. She was delighted to find a real princess for her son. Only a real princess would be sensitive enough to feel a single pea underneath 40 mattresses.

Soon after, the prince married the princess and they lived happily ever after. They put the pea in a museum, where it may still be seen if no one has stolen it.