Isaac Jones (1804-1850) was a translator of English works into Welsh, working at a time when most in Wales could speak only their own native tongue.

Jones was a native of Ceredigion. He was born on 2 May 1804 in Llanychaearn, near Aberystwyth. His father, a weaver, was his first teacher; he is said to have known some Latin at the age of seven. After this he went to a school in his parish and then to grammar school in Aberystwyth. He eventually became an assistant at his senior school and then, in 1828, headmaster. At this time, the school had as many as 100 to 120 pupils. Jones is said to have been short, but very overweight. In consequence, he was known as ‘Isaac the Fat.’ 

Jones was an early member of St David’s College, Lampeter. He entered the college in 1834; he was elected Eldon Hebrew scholar there the next year. He was ordained as a deacon in September 1836 and as a priest in September 1837. His first two curacies were still around Aberystwyth – Llanfihangel Genau’r-glyn and then Capel Bangor. While at Llanfihangel, he was also headmaster of the grammar school in the village. In February 1840, Jones moved to Anglesey, to become curate of Llanedwen and Llanddaniel-fab. He remained there until his premature death. 

Jones was an excellent Welsh scholar, grammarian and translator. Working with Owen Williams of Waunfawr, he was joint editor of the early Welsh encyclopedia, Y geirlyfr Cymraeg. (Although previous attempts at compiling a Welsh encyclopedia had been made in 1721 and 1795, this was the first successful effort at producing a Welsh language general encyclopedia.) Y geirlyfr Cymraeg was issued in forty-five parts; the first appeared in 1830 and the last in 1835. The complete work was published in two volumes, usually bound as one. Jones wrote the entire second volume. It became well-known and was a coveted household possession. 

Jones edited the second edition of William Salesbury’s New Testament; this was published in Caernarfon in 1850, a short time before his death. The works he translated into Welsh included Gurney’s Dictionary of the Bible (1835) and Adam Clarke’s Commentary on the New Testament (1847). Jones also helped Rev.  E. Griffiths of Swansea with the translation of Matthew Henry’s Exposition. Jones was the author of a Welsh grammar (1832, 1841) and several pamphlets and tracts. 

Jones never married. He died at Llanidan, on Anglesey, on 2 December 1850; he is buried in Llanidan churchyard.  


Thomas, D., & Millward, E.  (2004, September 23). Jones, Isaac (1804–1850), translator. Oxford Dictionary of National Biography. Retrieved 5 Jun. 2020, from 

Ellis, T. I., (1959). JONES, ISAAC (1804 - 1850), cleric and translator. Dictionary of Welsh Biography. Retrieved 5 Jun 2020, from

Samuel, D. (1894). The history of the grammar school (continued). The Aberystwyth Grammar School magazine. 4(2),17-21. Retrieved from 

Davies, J.I. (1984). The history of printing in Montgomeryshire, 1789-1960. Montgomeryshire collections relating to Montgomeryshire and its borders. 72,37-44. Retrieved from