It tells the story of a father who is carrying his sick son, while riding homewards after dark on horseback. The son is convinced that they are being pursued by the Erl-King, who speaks to him to persuade him to come away with him, while the father insists that the Erl-King doesn't exist — what he sees, so he tells the boy, are only trees, bushes and fog. Yet the boy will not be calmed, finally screaming that Erl-King is touching him. Even the father is horrified now, and rides the horse as fast as possible. When he arrives, he realizes that the boy is dead.
The poem was inspired by a Danish folk tale, which was translated to German as "Erlkönigs Tochter" ("Daughter of the Arlen King"). However Erlkönig is a mistranslation (by Johann Gottfried Herder) of the Danish "ellerkonge", which actually means "King of the elves" (that would be "Elfenkönig" in German, in case you wondered). It is possible that Goethe went with the "wrong" translation consciously, as the Erl-King does not fit in with what most people of the era would have recognized as an Elf-King; in the ballad, he seems to serve as a substitute to the Grim Reaper or Death. The "rational" interpretation is that the boy is hallucinating from fever.
"Erlkönig" is one the most recognizable of Goethe's works for Germans, thanks to its time-honored status as an inevitable school study medium. So is Zhukovsky's adaptation (see below) for Russians.
The poem was set to music (for solo voice and piano) by Franz Schubert in 1815. In Germany in the 20th century the word "Erlkönig" came to denote a car prototype on a nightly Autobahn test drive (speeding, like the father in the ballad, "through night and wind" and fog) in an attempt to evade photojournalists.
Some works and artists that reference the "Erl-King":
- Russian XIX-century poet Vassily Zhukovsky translated (or perhaps adapted, it wasn't a very literal translation) Goethe's ballad into a Russian-language poem "Лесной царь" ("The Forest Tsar") with the same plot.
- The Dresden Files - A powerful member of The Fair Folk goes by this name and the poem is acknowledge to be about him in-universe.
- John Connolly wrote a short story by this name about a boy who meets and just barely escapes the titular figure. Unfortunately, his infant brother doesn't have the same luck.
- Sarah Brightman - Her song Figlio Perduto uses an Italian adaptation of this poem for lyrics.
- Rammstein - Has a song titled Dalai Lama which is the Erlkönig on a plane.
- Roommates - Also has the Erlkönig as character, and a meta webcomic adaptation of the poem, which is his official backstory. He would also love to hear about that Alternate Character Interpretation mentioned in the main tropes.
- Doom Metal band Pagan Altar's "The Erl King" is an adaptation of the Goethe poem. Also, the Erl King is mentioned in "Armageddon" as being quite pleased with the nuclear war that destroys humanity.
- There is a quite famous Surreal Horror Labyrinth Dark Fic by Subtilior titled "Erlkönig". Let's just say the references don't stop at the title.
- Le Roi des aulnes: a 1970 novel written by Michel Tournier
- One episode of Boardwalk Empire is titled Erlkönig.
- Of course pathos begets countless parodies (eased by the fact that the poem is so easily recognized even when parodied). To name just one, "König Erl" by famous German comedy poet Heinz Erhardt.
"Erl-King" provides examples of the following tropes:
- Adult Fear: Having your child screaming for help and eventually dying in your arms.
- Death of a Child: The poem is about a farmer riding furiously through the night to get his sick son home. The feverish young boy becomes increasingly distraught, claiming that the Elf King is trying to take him. Whether the Elf King is really there and trying to kidnap the boy or if it's just a fever hallucination is left ambiguous, but by the time the father reaches their home the boy has died.
- Died in Your Arms Tonight: The last line of the poem: "In his arms, the child was dead."
- Downer Ending: By the time the father arrives home, his son has already died.
- The Fair Folk: The Erlking and his daughters.
- Faux Affably Evil: The Erlking shows his real face after his seductive approach doesn't work on the boy.
- Imaginary Enemy: The boy feels he is pursued by a supernatural entity which his father cannot see, and which wants to take him away to a supernatural realm against his will.
- It's Probably Nothing: The father repeatedly insists that what the boy sees and hears are from mundane sources, e.g. a tree or the wind.
- Maybe Magic, Maybe Mundane: The poem does not answer the question whether the Erlking is real or only the dying boy's fever dream.
- Not Now, Kiddo: How the father initially disregards the boy's fears.
- Not-So-Imaginary Friend: The father believes the Erlking is only a figment of the boy's imagination and keeps telling his son he does not exist, but by the end he "feels a horror" (dem Vater grausets), which indicates he (and with him, the reader) is left wondering whether the Erlking is real, after all.
- Would Hurt a Child: The Erlking offers violence against the boy.