I am fiery Taliesin.
I give Christendom song....
The Llyvyr Taliessin, or Book of Taliesin, is known from a fourteenth-century manuscript (known to scholars as Peniarth MS 2). In Middle Welsh form, it contains perhaps the oldest known Welsh poems, some of which may go back to the ninth century. It is possible, although much harder to determine, that some elements of some of the poems may go back as far as the sixth century; but it is certain that in language the poems as we have them are from the twelfth and thirteenth centuries. We know very little about how these poems came together, but while they are in very different styles and appear to be from very different authors, they do have a kind of thematic unity, because many of them are written either in the persona of the legendary sixth-century bard Taliesin or are at least are concerned with matters associated with him.
Taliesin is mentioned early as one of the great Welsh poets; he is associated with court of King Urien of Rheged, and the poems about Urien in the Book of Taliesin are the best candidates for having elements that genuinely do go back to the original Taliesin. That there was such a bard is historically quite certain -- we have sufficient number of distinct lines of evidence for it that it would be astounding if he didn't exist -- but most of what we know of him is later legend. According to one such legend, he began as Gwion Bach. He was a servant of the enchantress Ceridwen, who was attempting to create a potion of inspiration that could give the awen, the breath of poetry and prophecy; he was tasked with keeping it stirring. Three boiling-hot drops, however, landed on Gwion Bach's thumb, and he put his thumb in his mouth to cool it. Gwion Bach, now extraordinarily wise, fled lest Ceridwen kill him; he eventually turned himself into a bit of grain to hide, but Ceridwn found him and ate him. She became pregnant from that grain, however, and gave birth to Gwion Bach again. Unable to kill her own baby outright, she tied him in a bag and threw him into the sea, whence he was in a sense born a third time when he was found by a man named Elffin, who gave him the name Taliesin, which means 'radiant brow'. In the eleventh century, he began to be associated with the court of King Arthur, although historically he would probably have been a little later than the dates generally associated with Arthur. Regardless, he became The Welsh Poet, the figure who symbolizes them all; and, indeed, even today Welsh poets will sometimes write poems from the the perspective of Taliesin.
I will be reading the Penguin Classics version, The Book of Taliesin: Poems of Warfare and Praise in an Enchanted Britain, translated by Gwyneth Lewis (an award-winning Welsh poet) and Rowan Williams (also a poet, although best known for being the former Archbishop of Canterbury). There are sixty-one poems in the collection, which Lewis and Williams divide up into the following categories:
Heroic Poems (1-12)
Legendary Poems (13-38)
Prophetic Poems (39-49)
Devotional Poems (50-59)
Ungrouped Poems (60-61)