Tam Lin

"If my love were an earthly knight, As he's an elfin grey, I wad na gie my ain true-love For nae lord that ye hae."

Tam Lin is Child Ballad #39, stemming from the Oral Tradition, and one of the most popular ballads, both as a song and as a source for literature. It is from the south of Scotland, and was first recorded in the mid-sixteenth century.

In a nutshell: Headstrong young Janet hears that the mysterious Tam Lin has forbidden all maidens to go to the wood called Carterhaugh (a real place; it's near Selkirk), on pain of... how shall we put this... no longer being maidens. She declares that she will go to Carterhaugh, but she has no sooner picked a rose than Tam Lin himself shows up...

Some time later, a knight at Janet's father's court remarks that Janet looks knocked up. Janet agrees, but says the baby's father is not any of the men at her father's court. She returns to Carterhaugh and speaks to Tam Lin.

Tam Lin tells Janet that he was once mortal, but was captured by the Queen of the Fairies and is now in danger of being offered as a tithe to Hell. Janet can save him, he explains, if she waits by Miles Cross until midnight on Halloween, pulls him down off his horse, and holds on to him throughout his transformations. Janet does this, and the Queen of the Fairies is obliged to let Tam Lin go.

The numerous variants collected by Francis Child can be found here.

Tropes featured in the ballad

 * All Hallow's Eve
 * Dude in Distress
 * The Fair Folk
 * Fantasy Contraception
 * Hair of Gold
 * Human Sacrifice
 * Law of Inverse Fertility
 * Narrative Poem
 * Rescue Romance
 * Unspoken Plan Guarantee: Inverted
 * White Stallion

Works derived from this ballad

 * Diana Wynne Jones's Fire and Hemlock
 * Pamela Dean's Tam Lin
 * Janet McNaughton's An Earthly Knight
 * Elizabeth Marie Pope's The Perilous Gard
 * Elizabeth Bear's Blood & Iron
 * John Myers Myers's Silverlock contained a Shout-Out chapter.
 * While not a direct reference, there's a character called Tam Lin in Nancy Farmer's House of the Scorpion.
 * Charles de Lint's short story "The Butter Spirit's Tithe."
 * Tam Lin has shown up on several occasions in the Shin Megami Tensei series.
 * In Discworld, both Magrat's rescue of Verence in Lords and Ladies and Tiffany's rescue of Roland in The Wee Free Men have elements of Tam Lin. Magrat is even inspired by hearing the ballad, despite Shawn's insistence that real life isn't like folk songs.