[[caption-width-right:320:(by Maxfield Parrish)]]

[[http://www.surlalunefairytales.com/frogking/index.html "The Frog Prince"]] (also known as "The Frog King" or "Iron Henry") is an old German {{fairy tale}} recorded by Creator/TheBrothersGrimm.

The story begins when a young princess loses her golden ball down a well and a nearby frog offers to retrieve it for her. In return, however, he demands that she keep him near her as a close companion, and share her food, her drink, and her bed with him. The princess is repulsed by the frog, but, reasoning that he has no way to enforce the promise, agrees. The frog returns her ball, and she runs home without him.

Later that night, the frog appears at the castle, and the king insists on the princess keeping her promise to him. Come night-time, however, the princess refuses to let the frog sleep on her pillow, and angrily throws him against the wall. To her shock, what lands is a handsome (and very forgiving) prince, and the two of them [[LoveAtFirstSight fall in love]] and marry.

As they ride off into the sunset, they hear three loud cracks from outside the coach - it was the prince's faithful servant, Henry, who had had his heart bound with iron straps to keep it from breaking when the prince was enchanted. The cracking sounds were the bonds breaking as the man's heart swelled with happiness.

The iconic TrueLovesKiss that replaces the act of violence in breaking the spell seems to be an artifact of translations into English, and has [[LostInImitation completely replaced]] the earlier versions in popular culture, even in Germany. The ending with the faithful servant is also frequently left out.

The princess's violence may be a throwback to other animal-bridegroom type stories -- including frog prince ones -- in which violent acts (such as beheading the animal or burning its skin) were the only way to break the spell. Removed from this context, though, it gives the story a BrokenAesop; the moral up until that point has been that you must keep your promises. In abusing the frog, the princess is breaking her promise with a vengeance, leading the reader to wonder why she deserves the handsome prince. Versions in which she kisses him avert this problem. Other folktale variants have the frog transform merely by sleeping in her bed-- raising other issues when they are found together.

It is a wide-spread tale in Europe, with many variations on why she makes the promise: the frog may tell her how to carry water in a sieve (as ordered by her WickedStepmother), or let her get water from a well that will cure her mother.

The DistaffCounterpart "[[http://www.pitt.edu/~dash/type0402.html The Frog Princess]]" is also a widespread tale. In the former [[UsefulNotes/SovietRussiaUkraineAndSoOn USSR]], the princess version is way more well known than the prince version. The UsefulNotes/{{Russia}}n version also has a number of features: there, king's three sons shoot their bows randomly, and where the arrow falls, they'll find their wives. The younger son blindly shoots to the marshes, and as the Frog Princess finds his arrow, he has to marry her. Also, the Russian version does not end with frog's transformation back to a girl, but rather sets it as a starting point for more adventures.

A lesser-known [[Literature/EastOfTheSunAndWestOfTheMoon Norwegian variant]] features trolls and other mythical beasts who punish the girl and send her on a quest for disobeying her [[BalefulPolymorph enchanted animal companion]]. Contrast [[Myth/ClassicalMythology Persephone]]; and other fantastic-bridegroom myths, wherein the original {{aesop}} was made in part to help young women accept an ArrangedMarriage to someone they may not like very much ("Don't worry what he looks like, sweetie, he'll be a good husband if you're a good wife.")

!! "The Frog Prince" and its variations contain examples of the following tropes:
%% Zero context examples have been put under comments. Please write up a complete example before uncommenting.
* {{Animorphism}}: Man to Frog to Man.
%%* BeastAndBeauty
* BewitchedAmphibians: Probable TropeCodifier.
* BrokenAesop: You should keep your promises to people, unless they're gross.
* CompositeCharacter: In earlier variants, and the Grimms' original draft, there are usually more than one girl who encounter the frog. The first ones do not keep their promises to it, but the last one does and marries him when he becomes a prince again. The Grimm Brothers ultimately combined them into a complete bitch of a princess.
* CurseEscapeClause: Not specified in the Grimm version; in later versions, assumed to be TrueLovesKiss.
* CurseIsFoiledAgain: The prince turning back into a human thanks to the princess killing him or kissing him or just letting him spend the night in her bed.
%%* EverythingsBetterWithPrincesses
%%* HappilyEverAfter
* LicensedGame: The Prince is the AntiHero of the second game in the ''Videogame/DarkParables'' series.
* LostInImitation: In many adaptations, the kiss has supplanted the violence of the traditional versions.
%%* LoveAtFirstSight
* RuleOfThree: Iron Henry has three bands of iron around his heart.
* SettingUpdate[=/=]AnimatedAdaptation:
** Disney's ''Disney/ThePrincessAndTheFrog''
** Jim Henson's ''Film/TalesFromMuppetlandTheFrogPrince''
* ShotgunWedding: A Hungarian version just mentions that they want them quickly married when the couple are found in her bedroom -- just to make sure there's enough time between the wedding and the christening.
* ShirtlessScene: Creator/RobinWilliams as the prince in the ''Faerie Tale Theatre'' production of "The Frog Prince" is naked when he transforms back into a man, covered only by a ModestyBedsheet.
%%* SlapSlapKiss: In the original.
* TrueLovesKiss: In newer versions, starting with English translations.
* WickedWitch: Mentioned in passing, put the spell on the prince for reasons unknown.