Foster was a fully-equipped Celtic Scholar, with an enviable command of the major Celtic languages and their literatures; he was also deeply interested in the history and archaeology of the Celtic countries (as well as in several other kindred scholarly disciplines: for example, he was Chairman successively of both the Modern Languages Board and the Anthropology and Geography Board of Oxford University). There can be no doubt that he succeeded in much enhancing the esteem in which Celtic Studies were held at Oxford during his period as Professor there.
Foster excelled as a director of research, and at one time four of the five Professors of Welsh in the constituent institutions of the University of Wales were former students of his. No-one who had been directed by him could fail to feel deeply in his debt, personally as well as academically. So committed was he to teaching that he tended to accord a lower priority to research and publication, although everything he did publish was characterized by profound learning and sure judgement: see, for example, his Rhŷs Lecture The Book of the Anchorite (1950), his chapter on early Wales in the volume Culture and Environment which he co-edited with Leslie Alcock (1963) and his chapter on the earliest poetry in the volume Prehistoric and Early Wales which he co-edited with Glyn Daniel (1965). From ‘Cylch yr Hengerdd’ (the Early Poetry Circle), which he founded and which met twice or three times a year under his chairmanship at Jesus College, emerged the volume Astudiaethau ar yr Hengerdd (Studies in the Early Poetry), edited by Rachel Bromwich and R. Brinley Jones (1978) and dedicated to Foster ; Early Welsh Poetry (ed. Brynley F. Roberts , 1988) was dedicated to his memory. He did not, however, succeed in publishing his magnum opus on Culhwch ac Olwen (he was perhaps too much of a perfectionist) but this was completed for him in a series of four volumes by his friends Rachel Bromwich and D. Simon Evans between 1988 and 1997 — an act of extraordinary benefaction not only to Foster 's posthumous scholarly reputation but also to Welsh scholarship as a whole. Foster served a large number of learned and cultural institutions in both England and Wales. Here it is possible to mention only The Honourable Society of Cymmrodorion (whose Transactions he edited from 1953 till 1978), The National Library of Wales (Treasurer 1964-79, Vice-President 1977-84) and the National Eisteddfod of Wales (Chairman of the Council 1970-3, President of the Court 1973-7). He was elected a Fellow of the Society of Antiquaries in 1954 and dubbed KBE in 1977.
Foster died of heart disease on 18 June 1984 in the Caernarvonshire and Anglesey Hospital at Bangor and was buried in the graveyard of Glanogwen Parish Church in Bethesda : he had been brought up as a Calvinistic Methodist and never ceased to respect that tradition, but with the passage of time he found High Church Anglicanism to be a more congenial spiritual home. Astudiaethau ar yr hengerdd contains a photograph of Idris Ll. Foster .
Professor Robert Geraint Gruffydd, D.Phil., Aberystwyth / Bangor
Published date: 2008