Thomas the Rhymer (also Thomas Rhymer or Thomas Rymer) is the better-known name of Thomas of Erceldoune, a 13th Century Scottish soothsayer. Many people have encountered him in fictional form as the protagonist in the ballad Thomas the Rhymer (Child Ballad number 37).
Thomas was born in Erceldoune (also spelt Ercildoune – presently Earlstoun), Scotland, sometime in the 13th century, and has a reputation as the author of many prophetic verses. Popular esteem of him lived on for centuries after his death, to the extent that several people have fabricated Thomas' "prophecies" in order to further the cause of Scottish independence. His reputation for supernatural powers for a time rivaled that of Merlin, though while the latter was fictitious, Thomas of Ercildoune was an historical figure. Records have been found referring to the son of "Thomas Rymour of Ercildoune". The fifteenth-century romance "Thomas of Erceldoune" with its accompanying prophecies clearly relates to the ballad, though the exact nature of the relationship is not clear.
Musicologists have traced the ballad Thomas the Rhymer back at least as far as the 13th century. It deals with the supernatural subject matter of fairy-folk. The theme of this song also closely relates to another song, that of Tam Lin, which follows the same general topical lines. Its more general theme relates to temptation and mortal pleasures.
Several different variants of the story of Thomas Rhymer exist, most having the same basic theme. They tell how Thomas either kissed or had sex with the Queen of Fairyland and either rode with her or was otherwise transported to Fairyland. One version relates that she changed into a hag immediately after sleeping with him, as some sort of a punishment to him, but returned to her originally beautiful state when they neared her castle, where her husband lived. Thomas stayed at a party in the castle until she told him to return with her, coming back into the mortal realm only to realise that seven years (a significant number in magic) had passed. He asked for a token to remember the Queen by; she offered him the choice of becoming a harper or a prophet, and he chose the latter.
Thomas became known as "True Thomas" because he could not tell a lie. Popular lore recounts how prophesied many great events in Scottish history. (His gift of prophecy seems to link to that of poetry, as Thomas was a noted poet (hence, "Rhymer"), and allegedly wrote Sir Tristrem, a version of the Tristram legend.) After a number of years had passed Thomas returned to Fairyland, from whence he has not yet returned.