The Frog King or Iron Henry, also known as The Frog Prince and The Princess and the Frog, is a German folktale collected by the brothers Grimm from an unespecified member of the Wild family, first published in the first volumen of the first edition of Children and Household's Tales in 1812.
The oldest known variant of this story, that the brothers Grimm acknowledged in their annotations, figured in a Scottish book titled The Complaynt of Scotland, printed in 1549. In that book a story called The Well at the World's End is included, which tells the story of a girl who’s sent by her stepmother to the titular well to fetch water. In order to do so the girl, like the princess in the Grimm’s tale, must make a promise to the frog, although her betrothal to the frog is more explicit here. The girl returns home, and at midnight she hears the frog knocking at her door. She lets the animal in, and the prince recovers his human form.
A king has many beautiful daughters, but the most beautiful is the youngest, who likes to go to a forest nearby her father’s castle and play with her favorite toy, a golden ball, at the edge of a well. One day the ball falls into the well, and because the princess thinks he has lost her favorite toy she starts to cry. While she’s crying suddenly she hears a voice asking her why she’s crying, but when she looks around she only sees a frog. The princess explains to the frog what happened, and the frog asks her what she would give him if he recovers the ball for her, and the princess offers her clothes, her jewelry and even her crown, but the frog replies saying he’s not interested on any of that, the only thing he wants is to be the princess’ companion and sit right beside her at the table, eat from her plate and sleep with her on her bed. The princess accepts the deal, but actually thinks the frog is disgusting and there’s no way she’s not gonna share anything with him. After taking a dive on the well the frog recovers the golden ball, but the moment the princess has recovered her toy she grabs it and runs away, leaving the frog behind, despite the animal asking her to take him with her because he can’t run as fast as she does.
The next day the princess is sitting at the table with the rest of the court when they hear someone knocking out the door. The princess goes to see who’s knocking, and when she sees that is the frog she met yesterday she slams the door. Her father asks her who was knocking and why she slammed the door, and the princess tells him everything that happened yesterday. After hearing the frog outside calling for the princess, the king says to her daughter that she must keep her promises and orders her to let the frog in. The frog sits at the table right beside the princess and eats from the princess’ golden plate, enjoying the food, while the princess feels disgusted from what she’s seeing. When it’s time to go to bed the frog asks the princess to carry him to his bedroom, and the princess starts to cry because of the thought of having to share his bed with the frog, who she finds repulsive. But her father gets angry at her and she ends up having to take the frog to her room upstairs, grabbing him with two fingers. In the room she puts the frog in a corner, but while she’s laying on her bed he creeps into it and threatens to tell her father if she doesn’t share her bed with it. Sick and tired the princess has enough and throws the frog against a wall. After hitting the wall the animal turns into a handsome prince. The next day the prince and the princess go to the prince’s kingdom in a carriage, in whose rear stood the prince’s faithful servant called Henry, who felt so much grief when a wicked witch turned the prince into a frog that he placed three iron bands around his heart, so It wouldn’t burst. During the trip the prince hears three times a noise and thinks some part of the carriage has broken, but the noise is actually made by the iron bands around Henry’s heart, who feels so much joy for seeing his master again, finally disenchanted.
- The Frog King, German film directed by Alf Zengerling, released in 1940.
- The Frog King, West German film directed by Otto Meyer, released by 1954.
- The Frog King, North American film directed by Tom Davenport, released in 1980.
- The Frog Prince, North American Israeli co-production directed by Jason Hunsicker, released in 1986.
- The Frog King, East German film directed by Walter Beck, released in 1988.
- The Frog King, Czechoslovak film directed by Juraj Herz, released in 1991.
- The Princess and the Frog, North American animated film, released in 2009.
- The Prince of the Pond, Otherwise Known as De Fawg Pin by Donna Jo Napoli, published in 1992.
- Fair Peril by Nancy Springer, published in 1996.
- Water Song by Suzanne Weyn, published in 2006.
- Frogged by Vivian Vande Velde, published in 2013.
- Frogkisser! by Garth Nix, published in 2017.
- The Frog King, with illustrations by Binette Schroeder, published in 1989.
- A Frog Prince, with illustrations by Alix Berenzy, published in 1989.
- The Frog Prince, with texts by David Lloyd and illustrations by Jan Ormerod, published in 1991.
- The Frog Prince, Continued, with texts by Jon Sciezska and illustrations by Steve Johnson, published in 1991.
- The Prog Frince: A Mixed-Up Fairy Tale, with texts by C. Drew Lamm and illustrations by Barbara McClintock, published in 1999.
- The Frog Prince, with texts by Kathy-Jo Wargin and illustrations by Anne Yvonne Gilbert, published in 2007.
- The Frog King, with illustrations by Henriette Sauvant, published in 2012.