According to the legend Thomas was carried off by the Queen of Faery one day as he sat under the ‘Eildon Tree’ in the Tweed Valley in Scotland. The most well-known version of the story is the Ballad which tells briefly of his being carried off by the Queen on a white horse and told that they are taking neither the road to Heaven nor the road to Hell but a third way which leads “over the ferny brae” to “fair Elfland”. When he returns he has a tongue that can never tell a lie and the gift of poetic speech. The text of the Ballad is on another menu on this site HERE->.
Thomas of Erceldoune was a real person who lived in the Tweed Valley in the thirteenth century and had a reputation as a prophet and a versifier. A much longer version of the story about him is contained in a verse romance in a fifteenth century manuscript which describes the Queen (there called the Lady) in some detail which has a marked resemblance to the description of Rhiannon in the medieval Welsh tales collected as The Mabinogion. This much more extensive account of the story is followed by a series of prophecies relating to the conflicts between England and Scotland. A detailed comparison of the different versions of the story and their sources can be found HERE->.
Both versions contain initiatory elements involving travel underground, through water and even through blood to get to the Otherworld. Like other legendary poets such as Taliesin, Thomas has the power of prophecy as well as poetic inspiration. Other stories about him in Scottish folklore (e.g. THIS ONE->) portray him as a person able to cross the borders between this world and the Otherworld and as acting as an agent for the faërie folk.
In common with other stories of legendary bards Thomas’s legend has the elements of identity with a real person or authorial presence which develops into something more than the original identity and becomes the definitive type of the inspired poet, prophet or visionary crossing the boundaries between the worlds. Other elements within the folklore tradition are gathered in an enlarged story about an awenydd, an initiate of the mysteries or the mouthpiece for prophetic visions some of which have social as well as mystical significance, embodying the aspirations of the tribe in the public arena as well as inner spiritual wisdom.
Yg kynneir, o’r peir pan leferit: o anadyl naw morwyn gochyneuit
“So”, Taliesin said, “even when Pwyll went into Annwn, and throughout the time of his sojourn there, , no-one knew of Gweir imprisoned in Caer Sidi, no-one had been there. He dwelt there alone, singing a sad song. But we went, three shiploads of us sailed with Arthur in Prydwen, but of those only seven of us returned.”
It was a story he liked to tell and, not noted for his modesty, the part he played in that raid on the Otherworld was his main theme. It was him, he claimed, that first thought of it, going after the cauldron that was held there in that perilous place. They say it was kindled with the breath of nine maidens, that its rim had pearls on the dark edge of it. It’s virtues were many and various magical things could be done with it, but for him, always in pursuit of the awen, it was the source, the Cauldron of Inspiration, and all the other stuff was just trivia. Those nine maidens were the muses, and each of them had infused it with an element of the awen – three times three, three for the bards, three for the ovates, three for the druids: for bardic craft, learning and wisdom. These comprise the elements of song, but a tenth, the deep infusion of all of them, sung secretly in the heart of a true poet, that was his quest, and that was the song that Gweir sang, imprisoned in his lonely fort.
Could he capture this? So Arthur took him there, braved the engulfing waters, his men eager for the spoils of Annwn. But Taliesin had no patience with them, with men at arms or those who were supposed to be wise, dismissing the soldiers as sluggards with trailing shields, and the priests and scholars as men who knew nothing. Even his fellow poets didn’t fare well in his opinion. What did they know? He, on the other hand, knew everything. He was an awenydd, with the gift of the awen, a true poet blessed by the muse.
So when that man, ‘Death-Dealer’ they called him, stuck his sword in the cauldron and his mate ‘Leaper’ grabbed hold of it, he knew they would never leave that place. Just to have been there, to have looked upon it, to have heard Gweir’s sad lament, that was all he needed. Were they really with him at all? Yes, they went on a raid for loot, and a few of them came back. But which of them went into the Otherworld? Only him, if you know what he found there. No-one else knew, and it was nothing he could show you. But it was a prize he’d sacrifice an eye for if he had to.
This view of Taliesin sees him as the bard of the Brythonic chieftain Urien in the sixth century kingdom of Rheged which extended from Strathclyde (around modern Glasgow) down into Cumbria in the northern part of the Lake District. Of the mass of poems in The Book of Taliesin a few are still held to be possibly written by this poet. They mainly sing the praises of his lord in common with much of the poetry composed by tribal bards at this time. But The Book of Taliesin is a fourteenth century manuscript collection given that name when discovered in a library in the seventeenth century. So the poems in it are not, in the form we have them, from the sixth century but later copies. As, initially, no-one could read them, they were assumed to be the work of a poet writing in Old Welsh. By now it has been established that most of the poems must be much more recent than that and all are, in fact, written in Middle Welsh in the manuscript versions we have.
If that was all that could be said, Taliesin would be no better known than Aneirin, another poet from what is now southern Scotland writing around the same time, who composed a series of elegies for the members of the Gododdin tribe who were wiped out in an attack on the Angles at the battle of Catraeth (modern Catterick in Yorkshire). That is, as with Aneirin, the debate about him would mainly be restricted to scholars attempting to date the poems from linguistic and historical evidence or discussing their contribution to the successive literary tradition in Welsh.
But Taliesin, like Myrddin, a third poet identified with the same area, has been mythologised in a number of ways. And if the mythologisation of Myrddin as Merlin is at least clear and transparent, Taliesin has been transformed into a much more complex wizard for later generations.
(2) The Legendary Bard
Many of the poems in The Book of Taliesin contain prophecies which link them to historical events in the ninth and tenth centuries. Others refer to stories that link them with prose tales in Y Mabinogi. Or with legendary exploits such as the raid by Arthur on Annwfn – the Brythonic Other World – to capture a magical cauldron. What is clear from consideration of the range of poems attributed to Taliesin is that, like Arthur, his name became a magnet for disparate material but also that he became the ‘type’ of the inspired poet. When later generations of Welsh poets in the Middle Ages looked back to the sources of their tradition, the place of beginning was ‘The Old North’, an area of southern Scotland and Northern England. Here the earliest poets using Welsh after it had developed from the Brythonic language some time after the Roman occupation, were seen as forefathers of the Welsh bardic tradition – one was called ‘Tad Awen’ (Father of the Muse) by Nennius in the 9th century, though none of his poems have survived. Collectively they were called the ‘Cynfeirdd’ (the earliest poets) and Taliesin became their iconic representative. So already, by the ninth century, he was being represented as a prophet and a magical figure who was present (whether imaginatively or otherwise) at various historical and legendary events from the beginning of the world to Arthur’s raid on the Other World. He was, in the Second Branch of Y Mabinogi, one of the seven who returned with the head of Brân from Ireland and sojourned with that head in Gwales in a timeless suspension of the everyday world. This is the poet as ‘awenydd’, an inspired individual such as those described by Gerald of Wales in the twelfth century, going into a prophetic or visionary state. He could now be regarded as the Spirit of Poetry.
(3) The Spirit of Poetry
At some point, inevitably, Taliesin entered the folklore tradition. The familiar story about Gwion Bach being given the job of stirring the cauldron of the witch Ceridwen and gaining universal knowledge by tasting a drop of the contents using a common folklore narrative pattern. Similarly the sequence of shape-shifting as Ceridwen chases him and each turn into something different until she, as a hen, gobbles him up when he is disguised as a seed. His rebirth from her womb, his survival in his new identity as Taliesin, and his subsequent exploits at the court of Maelgwn Gwynedd, link this story to the legend of the gifted poet. In one sense this is just another example of the ‘magnet’ effect mentioned above, with the name Taliesin simply being attached to existing folk tale motifs. But in another sense it indicates how the figurative shape-shifter has become a ‘type’ not just of the Welsh bardic tradition but of the Spirit of Poetry itself.
Patrick Ford in his discussion of Ystoria Taliesin (the sixteenth century prose tale in Welsh based on his continued presence on the folk tradition) says this:
“Clearly the tales of Gwion Bach and Taliesin cannot be lightly dismissed as “folktale” or late developments. Perceptible in them and in their attendant poems, despite the layering of successive generations and external influences, lies the myth of the primeval poet, in whom resides all wisdom.” 
Patrick Ford sees the story of Gwion being swallowed by Ceridwen and cast into the waters in a leathern bag to emerge as Taliesin as a death and rebirth theme, still being retold in the version known as Ystoria Taliesin. He presents this as the poet sacrificing himself to his muse, to be compared therefore with mythological figures such as Odin sacrificing himself to himself, and with representations of the Spirit of Poetry in Irish stories such as the one discussed HERE. He defines the ideal form of the awenydd or inspired poet and the condition that such a figure aspires to attain.
Many of the elements in the folktale can be found in the poems of The Book of Taliesin. For instance, in a number of the poems the source of poetry is identified as a cauldron, most often identified as the Cauldron of Ceridwen. But in one poem there is a quite dense poetic construction in which the word for cauldron (peir) can also mean ‘sovereign’ which is often used as a metonym for God. So the words
“pan doeth o peir / ogyrwen awen teir” can be translated
“when there came from the cauldron / the ogyrwen of three-fold inspiration”,
or they could equally be translated as
“when there came from the Sovereign (God) / the three aspects of inspiration”.
In the most recent scholarly edition of these poems Marged Haycock describes this as “a nicely calculated ambiguity”, indicating that both meanings are intended here. The Book of Taliesin is a difficult text to interpret even for scholars and the poem from which these lines come – Kadeir Teÿrnon – has been described as bewildering and unintelligible. So any interpretations are provisional. But from its use here and elsewhere it is clear that ‘ogyrwen’ is the name of at least one of the three divisions of awen, or it is a term describing all three ( so, ‘the three ogyrwen of awen’). But what is clear is that the poem deliberately conflates the cauldron and God (as the Trinity) as its source. We might regard this as a neat bit of theology or an example of clever bardic word-wizardry of the sort the Taliesin figure often boasts about.
This reference is, in fact, just one example of a debate about the nature of awen among the early Welsh bards. In a discussion of this issue Patrick Ford cites an exchange between the bards Rhys Goch and Llywelyn ap Moel about the source of awen as to whether is comes from the “Holy Spirit” or from “The Cauldron of Ceridwen” and also cites a line from another medieval Welsh bard, called Prydydd y Moch, who conflates the two options with the line “The Lord God gives me sweet awen , as from the cauldron of Ceridwen”. It is thought that Prydydd y Moch might have written some of the poems in The Book of Taliesin and so would be Taliesin himself in his thirteenth century guise. That is, he would have adopted the Taliesin persona for the purposes of an awenydd rather than in the context of his duties as a court poet for which he would use either his own name or his recognised bardic title (Llywarch ap Llewelyn/Prydydd y Moch ).
Patrick Ford comments; “It seems appropriate that the persona of Taliesin, as representative of the old native tradition, should insist on the magical origins of awen and its use as a vehicle for traditional kinds of knowledge.”  But he also refers to the view of Marged Haycock that the medieval Welsh bards were also working within the context of Christianity and the persona of Taliesin also had to function within this world view rather than as a “druid desperately making a last stand for paganism”. He looked both ways, expressing current Christian thinking about God conceived of as a Trinity, locking this into the concept of the threefold nature of awen, but also maintaining his status as one who had links back to the older world.
So Taliesin denounces the other bards not as Gildas had done for their ungodliness, but because they have lost touch with the real roots of poetry, with the authentic awen. At the same time he ensures that he cannot himself be accused of being ungodly. But alongside this older notion awen is a developing concept during the Middle Ages and its divine nature necessarily takes on the prevalent Christian sense of divinity.
By the end of the eighteenth century, when Iolo Morganwg was putting together the scattered remnants of this tradition and the process of re-interpreting it was getting under way, the awen became the central symbol and ideal expression of the druidic renaissance as it is still held to be today both in the religious practice of druidry and in the continuing bardic tradition among Welsh language poets.
 Patrick Ford Ystoria Taliesin (Cardiff, 1992)
 Marged Haycock Legendary Poems from the Book of Taliesin (CMCS, 2007).
 Patrick Ford’s introduction to his edition of Y Mabinogiand Other Medieval Welsh Tales (1977) which contains the story of Gwion Bach and Taliesin.
 ‘Preiddeu Annwn and the Figure of Taliesin’ in Studia Celtica18/19, as cited by Ford, though since this article was published Marged Haycock has developed her ideas in greater detail in the work cited at  above and in also her more recent Prophetic Poems from the Book of Taliesin (2013).
I am the nakit Blynd Hary
That lang has bene in the fary
Farleis to fynd …’
* I am the naked Blind Harry
That has lingered long in Faery
Fey things to find …
These are the words of the Scottish poet William Dunbar (1459?-1530?) in ‘The Manere of the Crying of Ane Playe’ with my adaptation to current English following. The words are spoken by a dwarf who identifies himself with ‘Blind Harry’ a poet from a previous generation to Dunbar and one he wrote about elsewhere in his ‘Lament for the Makars’, a poem celebrating what Dunbar regarded as Scotland’s bardic heritage. Although Blynd Hary (‘Harry the Minstrel’) was apparently the author of a popular poem about the scottish hero William Wallace, he was also a legendary figure much like the welsh Taliesin, the vehicle for inspired, prophetic or magical verses that the poets who wrote them might not wish to put their names to. The dwarf here claims just such an ancestry for Harry, making him an habitué of the Otherworld and a descendant of Finn McCool:
My foregrantschir hecht Fyn McKowle,
That dang the Devill and gart him yowle
The skyis ranyd quhen he wald scowle
And trublit all the air
* My forefather was Finn McCool
That man who made the Devil howl
The skies cracked when he would scowl
And troubled all the air
What we have here is the characterisation of Finn as an ancestor to a speaker who frequents the Otherworld, continuing a traditional Irish theme still alive in medieval Scotland.
There is also a fascinating association between Finn and the Cailleach, for such, surely, is his ‘wife’ in this section of the poem:
He had a wyf was lang of clift
Hir head wan heiar than the lift
The hevyne reddit quhen scho wald rift;
The las was no thing sklender.
* He had a wife, she towered high
Her head was lifted to the sky
The heavens shifted when she passed by;
She was no slender lassie.
It is also said that she “She spittit Lochlomond with her lips” and that “Thunner and fireflaucht flew fae her hips” Thunder and lightning emanating from her seem to indicate her control of the weather. The ironic tag “The las was no thing sklender” reinforces this with characteristic humour.
In his The Book of the Cailleach (an essential text) Gearóid Ó Crualaoich says of her ; “ … the Otherworld female, the Cailleach of the Irish and the Scottish Gaelic tradition, regarded as the shaper who has formed the features of the landscape”. And later on in the Book, he suggests that “a kind of harmonious balance has existed, over many cycles of renewal of the Cailleach between the human and the Otherworld orders”.
Gearóid Ó Crualaoich writes of her as she appears in the oral folklore of Ireland and Scotland. That Dunbar made this reference in the literary tradition without the need for contextual comment in his evocation of a legendary bardic figure indicates how pervasive she must still have been in the consciousness of medieval scots along with Finn who, of course, does also have a presence in the literary tradition of both Ireland and Scotland.
A final note on Blind Harry: Some commentators have felt that his name relates to Hár an alternative name for Óđinn. This may be a coincidence. But, if there is anything in it, it does suggest a tantalising crossover between the Gaelic and the Norse pantheons in the name of a legendary bardic figure in medieval Scotland.