His chief claim to fame is as a copyist and collector of old manuscripts , and the influence of Edward Lhuyd (q.v.) on his career is marked. Nor should we forget the importance of the sources, such as the library of William Lewes (q.v.) of Llwynderw , which existed in his neighbourhood. Later, there arose a band of copyists in Carmarthenshire , all influenced by Iaco ap Dewi : William Bona of Llanpumpsaint ; David Richards , curate of Llanegwad ; and Ben Simon of Abergwili (q.v.) . Some of his manuscripts were acquired by Siôn Rhydderch and, later, by Lewis Morris . It should be emphasized that he displayed a critical judgement in preparing the texts and that there is evidence that he was a professional copyist , preparing the manuscripts for others, and travelling widely, e.g. to the well-known library at Pen-y-benglog , Pembs. , to collect his material. The best proof of the importance of his work lies in the fact that he and Samuel Williams (q.v.) have transcribed in Llanst. MS. 133 a large number of poems of which no other copy exists. Iolo Morganwg had learned from his friend Tomos Glyn Cothi (q.v.) something about Iaco ab Dewi 's manuscripts, but the claims he makes on his behalf are untrustworthy.
Moses Williams testifies that Iaco ap Dewi assisted Stephen Hughes to collect the poetic works of Vicar Prichard , and it is certain also that he collected traditional songs , etc., from the actual singers . It seems likely that he was the editor of Flores Poetarum Britannicorum , 1710 . The few poems which he himself wrote are not important except for the sidelights they throw on his own poverty and the melancholy conditions in which he lived; except, too, that they show him attempting to imitate some of the poets whose works he was transcribing as in his cywydd ‘ Molawd i'r Iesu .’ Among his manuscripts was a copy of the bards’ grammar. It is quite clear that he was not interested in the ballads and popular songs of his district; and any connection between him and the eisteddfodau of the period was purely fortuitous.
Moses Williams asserts that Iaco was forced by poverty to turn to translation as a means of eking out his livelihood and that he was patronized in this respect by the gentry and Nonconformists of Carmarthen . His eight translations were published between 1714 and 1730 . The most remarkable of these is his translation of Daily Communion with God , 1714 , and the best known that of Particular Thoughts on Religion , 1717 . It is possible that Iaco ap Dewi was one of the four who, according to Stephen Hughes , were employed in translating the Pilgrim's Progress , but there is no evidence to support this in the book itself.
Garfield Hopkin Hughes, M.A., (1912-69), Aberystwyth
Published date: 1959