Unlike Tam Lin, there is evidence that Thomas the Rhymer (also Thomas of Ercildoune and True Thomas) was a real person as well as a hero of a popular ballad. In the thirteenth century, Sir Thomas was born and lived in Ercildoune (now Earlston) in Berwickshire. Over time, possibly within his life time, he gained a reputation as an author of prophetic verses and being unable to tell a lie. He is mentioned in two charters from that century, one of which mentions a son also called Thomas. It’s unclear how early True Thomas started to gather his reputation and many of the prophesies attached to him in folklore are apocryphal and often borrowed from someone else. However, the gift of prophecy is clearly linked to his abilities as a poet to the point where it has become unclear whether “Rhymer” was a family name or an agnomen, although the second charter mention would suggest the latter.
The ballad of Thomas the Rhymer was catalogued as Child Ballad #37 in 1883. The basic storyline presented in the variants is of a young man lured to “Elfland” by the elf queen (see: the Fair Folk). He remains as her lover for seven years and then is returned to the place he was taken from. The queen offers him the gift of song or the gift of truth. He takes the latter and becomes a prophet.
Despite being taken to Elfland (a typical folkloric name for the Otherworld), there are no real indications that Thomas was marked by his time there in the ballad. The poetic abilities, the prophecies and the truth-telling are not known side-effects of time in the other reality. There are no markers of Second Sight as we have come to recognise it or of the Allergy, which he might be expected to have gained from seven years of living on Otherworld food. The only thing that might be surmised is that, whomever or whatever the elf queen might have been if she was real, the relationship was probably sustained by the Lust.