The Barddas of Iolo Morganwg, Vol. I., ed. by J. Williams Ab Ithel, [1862], at sacred-texts.com
At length here is an account of symbols and speech, namely, letters and signs, according to their preservation by means of the memory, voice, and usages of the Chair and Gorsedd of the Bards of Glamorgan and Gwent in Tir Iarll, 1 and previously at Caerleon-upon-Usk, since the first arrival of the Cymry in this island. They say that three privileged arts were introduced by the Cymry tinder the protection and guidance of Hu the Mighty 2 into this island; namely, Bardism, Literature, and Agriculture; that is, they were brought from Asia, as it is now called. Deffrobani, 3 however, or the Summer Country, was the first name of the primitive country of the nation of the Cymry, in which country were large and rich kingdoms without number. An usurping nation drove the Cymry out of their country into countries where for upwards of two hundred years they were roving from land to land under the oppression of devastative and predatory nations, until at last they landed in Scandinavia and the highlands of Italy, and the region of Gaul. It was from Scandinavia that they first came into the island [of Britain,] having landed at the river Humber. 4 After that other clans of Cymry came from the land of Gaul into this island, landing at the fords of Pwyth Meinlas, 5 but the usurping nation of the Coranians 6 drove
them to the South, whilst the Irish Picts drove the Cymry of the land of Deivr and Bernicia, who were derived from the Cymry of Scandinavia, to Venedotia; after that, the Irish of Ireland oppressed them in Mona and Arvon. Ten from the beginning was the number of the symbols of the Coelbren, and they were called Abcedilroes and Abcedilros, as they are called at present, that is, and . Subsequently, in the time of Prydain [son of ] Aedd the Great, others were added until they were sixteen symbols, and they continued of that number until the coming of Christ in the flesh; then eighteen, and after that twenty, or, as others say, twenty-one symbols primarily as at present, whilst others were invented as auxiliaries, in number as far as thirty-eight.
83:1 p. 82 "Cai Hir, nephew of the emperor Arthur, lord of the Comot of Maes Mawr in Glamorgan, was the first who appointed a Chair of Vocal Song in Tir Iarll, which was anciently called the Comot of Maes Mawr, whither it had been re-moved from Caerleon upon Usk, on account of the surrounding incursions of the Saxons. It was still called there the Chair of Caerleon. In the time of the contests between Rhys, son of Tewdwr, and Iestyn, son of Gwrgant, the Chair was disturbed, until the time of William, earl of Gloucester, who renewed it in Tir Iarll, (the earl's land,) for such, after his appellation, was the new name bestowed upon the Comot of Maes Mawr, and gave privilege and license to Bards."--Anthony Powell.
83:2 Geraint, the Blue Bard, has recorded a tradition respecting some of the services which Hu the Mighty showed to the Cymry, preparatory to their journey from Deffrobani:--
The achievement of Hu the Mighty, was forming social order
For the Cymry of the Isle of Britain,
To stream out of Deffrobani.--Iolo MSS. pp. 262, 669.
83:3 p. 83 Probably Taprobane, the island of Ceylon, is meant; celebrated as having been the residence of Adam. The Historical Triads, however, identify "the summer country" with that "in which Constantinople now is." (Tr. 4. 56; Third Series.)
83:4 "They came across the Hazy Sea to the island of Britain and Armorica where they remained." (Tr. 4; Third Series.)
83:5 Anglice "the narrow green point," where also the Romans are said to have landed under Julius Cæsar. (Tr. 22; Second Series.)
83:6 The Coranians are described as the first of "the three usurping hordes that came into the Isle of Britain, and went not out of it," (Tr. 7; Third Series;) and as having in course of time "coalesced with the Romans until they became one people," and ultimately with the Saxons, "against the Cymry." (Tr. 15; ib.) They were evidently the same as the Coritani.