The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, , at sacred-texts.com
This is what I, Llywelyn Sion, 2 took from the Book of Davydd Benwyn, 3 which is called the Coelbren of the Bards.
Here is the system of the symbols of letters, or the symbols of language and speech, as it was arranged by Gwilym Tew, 4 Bard and Chair Teacher, and exhibited at the Eisteddvod of the Chair and Gorsedd of Pen Rhys Monastery, 5 when Owain Glyndwr and the Cymry were prevailing against the Saxons. 6
There were ten symbols of letters in the possession of the Cymry from the beginning, before they came into the Isle of Britain, which ten are now kept an undivulged secret by the Bards of the Isle of Britain, and therefore no man can radically understand the Coelbren of letters, who is not under the obligation of the vow of the secret of the Bards of the Isle of Britain. In the time of Dyvnwal Moelmud, son of Dyvnvarth, son of Prydain, son of Aedd the Great, the symbolic cuttings of language and speech were augmented
p. 64 p. 65
to sixteen in number, and they were mutually divulged, and to each was given a new form, other than what the ten symbolic points that are secret and undivulged have. In the time when Bell the Great, son of Manog, 1 was king paramount of the Isle of Britain, the sixteen symbols were laid open to the nation of the Cymry, and security was given that there should be no king, judge, or teacher of country, without knowing the sixteen signs, and being able to reduce them into proper art. It was ages after that, before understanding respecting the symbols of Plagawd, that is, dressed skins, was obtained, and when that took place, the Roll was invented, and after that, the Books that are now seen in use. The number of the symbols was augmented until they were found to be eighteen in the time of Taliesin, chief of Bards, who employed them in his canons, hence the improvement of vocal song. After that the number of the symbols was raised to twenty, that is, the primaries, as at present. After that Geraint, the Blue Bard, began to use auxiliary symbols, which he invented, and which others, after him, improved, and the Bards kept memorials of them. When Owain Glyndwr was lost, plagawd and paper were prohibited in Cymru; and the Bards and Teachers, and all others who were required to keep memorials, were obliged to restore into sight and use the symbols of the Coelbren of the Bards, until the making them ready for the cutting became an art. Then they became infinitely numerous by the hands of sieve and basket makers, who sold them to any one that sought for them, and so they continued down to the days of those who are now living. It is Davydd Benwyn that says it.
63:2 p. 62 Llywelyn Sion was an eminent bard of Glamorgan, distinguished for having been appointed to collect the System of Bardism as traditionally preserved in the Gorsedd Morganwg, in which he presided in 1580. A great portion of the present Volume is due to his care and assiduity.
63:3 p. 63 Davydd Benwyn was a Bard who flourished from 1550 to 1600, being a native of Glamorganshire. He presided at the Glamorgan Gorsedd in 1580.
63:4 A Gwilym Tew presided at the Glamorgan Gorsedd in 1460.
63:5 The Monastery of Pen Rhys was suppressed in the second year of King Henry V.'s reign, AD. 1415, because its inmates had sided with Owain Glyndwr.
63:6 The insurrection of Owain Glyndwr began about 1400, and continued with varied success for fifteen years, when he died, i. e. September 20th, 1415.
65:1 p. 64 I.e. Manogan.