Taliesin, Chief Bard of Britain
"As soon as Elphin saw the forehead, he said, 'behold the radiant forehead!' (i.e. tal iesin)."
--Ystoria Taliesin, 16th C.
The bard Taliesin is a disputed character. Some evidence indicates he truly exited, while the stories about him are obviously ancient myths attached to his name. These myths lead some to believe, like Robert Graves, that there were three Taliesins--a god of poetry, a sixth century poet who served under King Urien of Rheged, and a thirteenth century scholar who wrote what is known as the Llyfr Taliesin, a collection of the poetry of Taliesin 2 and Taliesin 3, with bardic fragments attributed to Taliesin 1.
As a god, Taliesin is similar to Fionn MacCumhill, who gained knowledge from the Salmon of Wisdom. He is a shape-shifter, and is often associated with the Children of Llyr. His original name was Gwion Bach--literally, "Fair Boy". (It is worth noting that "Gwion" and "Fionn" are the same name, but in different branches of the Celtic languages.) However, upon drinking the magic potion of Cerridwen, he became enlightend--"gained awen" (poetic inspiration).
The historical Taliesin was a bard who lived in the 6th century, and was tied to the House of Rheged, as assumed by the large number of poems written for Urien of Rheged and his son Owein ap Urien (yes, these are the same as Urians of Gorre and his son Yvain of Arthurian romance). This Taliesin is said in some manuscripts to have been the son of a St. Henwg, and friend to Myrddin Wyllt, the later Myrddin who fought in the Battle of Arthuret.
To say that Taliesin was a bard is to admit that what we know of the status of "bard" in the sixth and seventh century is very small. Originally, bards were a subset of the druids, the priestly caste of the Celts. As such, they had a religious and social function. What of this function continued into the Christian era is up to debate. Certainly, even in the very late Llyfr Taliesin, which was presumed to have been transcribed at a monestary (Strata Florida is one supposition), yet the poems are filled with allusions to gods and druids. One doubts that the monks were ignorant of the original role of the bards. However, whether this reflects the role of the historical Taliesin is unknown.
The poems of Taliesin are found in three groups:
There are also poems attributed to Taliesin (or variations on poems found in the LT) which can be found in the The Black Book of Carmarthen and the The Red Book of Hergest.
Finally, there are several short biographies on Taliesin collected by Charlotte Guest, which may or may not be forgeries by Iolo Morgannwg.