Wikipedia’s Thomas the Rhymer page gives a good account of the legend, the historical Thomas, the ballad and all its sources. I was aware of many of these when I wrote the novel.
Terri Windling’s typically brilliant posted essay, “The Child Ballads (Part II)” from her “Into the Woods” series goes into more detail about the source ballads, and contains a quote from me about writing the novel.
Here’s an overview, from Mysterious Britain, and the ballad itself:
Thomas the Rhymer was a famous Scottish prophet who is also known as Thomas of Ercildoune, Lord Learmont and True Thomas. There can be no doubt that he was actually a real person living in the thirteenth century, as documents exist signed by him as Thomas Rymour de Ercieldoune. It is difficult to find any more evidence about his life, but the traditions that have built up around him must have some root in real events.
There are many accounts of his prophecies printed in chapbook form from the sixteenth century onwards. It is said that he gained his powers of prophecy from a meeting with the Queen of Elfland. He travelled with her for forty days and forty nights into the underworld, and served her for seven years. He then returned to the upper-world endowed with the gift of a tongue that can not lie, which he is said to have protested against.
One of his most famous prophecies involved the crowning of James the VI of Scotland or the I of England. He said that when the Tweed flooded into Merlin’s grave, Scotland and England would have one king. This happened at Merlin’s grave in Drumelzier when James was crowned.
Thomas is said to have returned to fair Elfland. He was feasting at his castle, when word came that a white hind and doe were walking calmly around the village streets. Thomas took his leave from the castle and was never seen again.
Although he is thought to have returned to the fair realm he makes notable appearances in other later tales such as Canobie Dick, and can be seen as a mediator between this world and the otherworld.
This is a role he serves with other figures such as the Reverend Robert Kirk and archetypal figures such as Merlin.
In James Francis Child’s monumental 19th century collection of ballad texts, The English And Scottish Popular Ballads (1882-1898) — commonly known as the Child Ballads — “Thomas Rymer” is “Child Ballad Number 37,” with three variants printed. The text below is 37C, from Minstrelsy of the Scottish Border, II, ed. 1802 of Sir Walter Scott, an avid ballad collector in his native Scots Lowlands. The fact that Scott was also a major poet and novelist surely could not have induced him to tidy it up and add any extra verses, oh dear, no:
|1||True Thomas lay on Huntlie bank,
A ferlie he spied wi’ his ee,
And there he saw a lady bright,
Come riding down by the Eildon Tree.
|2||Her shirt was o the grass-green silk,
Her mantle o the velvet fyne,
At ilka tett of her horse’s mane
Hang fifty siller bells and nine.
|3||True Thomas, he pulld aff his cap,
And louted low down to his knee:
‘All hail, thou mighty Queen of Heaven!
For thy peer on earth I never did see.’
|4||‘O no, O no, Thomas,’ she said,
‘That name does not belang to me;
I am but the queen of fair Elfland,
That am hither come to visit thee.
|5||‘Harp and carp, Thomas,’ she said,
‘Harp and carp along wi me,
And if ye dare to kiss my lips,
Sure of your bodie I will be.’
|6||‘Betide me weal, betide me woe,
That weird shall never daunton me;’
Syne he has kissed her rosy lips,
All underneath the Eildon Tree.
|7||‘Now, ye maun go wi me,’ she said,
‘True Thomas, ye maun go wi me,
And ye maun serve me seven years,
Thro weal or woe, as may chance to be.’
|8||She mounted on her milk-white steed,
She’s taen True Thomas up behind,
And aye wheneer her bridle rung,
The steed flew swifter than the wind.
|9||O they rade on, and farther on-+-
The steed gaed swifter than the wind-+-
Untill they reached a desart wide,
And living land was left behind.
|10||‘Light down, light down, now, True Thomas,
And lean your head upon my knee;
Abide and rest a little space,
And I will shew you ferlies three.
|11||‘O see ye not yon narrow road,
So thick beset with thorns and briers?
That is the path of righteousness,
Tho after it but few enquires.
|12||‘And see not ye that braid braid road,
That lies across that lily leven?
That is the path of wickedness,
Tho some call it the road to heaven.
|13||‘And see not ye that bonny road,
That winds about the fernie brae?
That is the road to fair Elfland,
Where thou and I this night maun gae.
|14||‘But, Thomas, ye maun hold your tongue,
Whatever ye may hear or see,
For, if you speak word in Elflyn land,
Ye’ll neer get back to your ain countrie.’
|15||O they rade on, and farther on,
And they waded thro rivers aboon the knee,
And they saw neither sun nor moon,
But they heard the roaring of the sea.
|16||It was mirk mirk night, and there was nae stern light,
And they waded thro red blude to the knee;
For a’ the blude that‘s shed on earth
Rins thro the springs o that countrie.
|17||Syne they came on to a garden green,
And she pu’d an apple frae a tree:
‘Take this for thy wages, True Thomas,
It will give the tongue that can never lie.’
|18||‘My tongue is mine ain,’ True Thomas said;
‘A gudely gift ye wad gie to me!
I neither dought to buy nor sell,
At fair or tryst where I may be.
|19||‘I dought neither speak to prince or peer,
Nor ask of grace from fair ladye:’
‘Now hold thy peace,’ the lady said,
‘For as I say, so must it be.’
|20||He has gotten a coat of the even cloth,
And a pair of shoes of velvet green,
And till seven years were gane and past
True Thomas on earth was never seen.
Here are Professor Child’s original scholarly notes on the “Thomas Rymer” ballad and all its variants.
And here are the shorter (and more easily digested) notes written by Child’s student, Professor George Lyman Kitteridge (1860-1941).