Meic Stephens, who has died aged 79, was one of the most productive and influential figures in Welsh writing in English. After a few years teaching in Ebbw Vale, and one as a journalist in Cardiff, in 1967 he joined the newly designated Welsh Arts Council, which he served as literature director for 23 years. He had no background in arts administration, but in the early 1960s, while still teaching, he had established his own publishing imprint, the Triskel Press, and in 1965 launched Poetry Wales.

Under his editorship the magazine was committed to the causes of Welsh nationhood, the Welsh language and building bridges between what were then known as Anglo-Welsh writers and those who wrote in the senior language of Wales. It became the principal vehicle of “the second flowering” of Welsh writing in English (the first having been in the 1930s). Among the new voices it introduced in the late 1960s and 70s were Gillian Clarke and Robert Minhinnick; it also resuscitated lapsed talents such as those of John Ormond, Leslie Norris and Harri Webb, bringing them to impressive maturity.

The role of literature director, for which there was no template, Meic largely invented himself. He was full of ideas, and had the political nous and the energy to steer them through the literature committee. Much of the achievement during the second half of the 20th century in raising the ambitions and standards of writers and critics in Wales, and the quality of book production, can be traced back to him and his productive relationships with committee chairs, notably Glyn Tegai Hughes, Roland Mathias, Walford Davies and M Wynn Thomas. So evident was the worth of several literary initiatives pioneered in Wales that they were adopted by other UK arts councils.

He also contrived to maintain a high level of activity as writer and editor. When an undergraduate he had seen himself as a poet rooted in industrial south Wales, but he was not prolific and published little in the English language after Exiles All (1973). In later years, however, on several occasions he came close to winning the Crown at the National Eisteddfod for poem sequences in Welsh, his third language. Linguistic Minorities in Western Europe (1976) revealed the depth of his interest in the rich diversity of European languages and cultures, and in later years he published translations from Welsh and French.

Above all, perhaps, he will be remembered for his skills as compiler and editor, demonstrated most notably in his editorship of The Oxford Companion to the Literature of Wales (1986) and (jointly with Dorothy Eagle) The Oxford Illustrated Literary Guide to Great Britain and Ireland (1992). As editor he knew many of his contributors personally, as he knew writers and publishers, in English and Welsh, the length and breadth of Wales. His literary acquaintance extended throughout the UK and in several countries overseas, for he was interested in people, enjoyed company and was an engaging and amusing companion.

Meic was born in Trefforest, near Pontypridd, to Arthur Stephens, a power station worker, and his wife, Alma (nee Symes). He later recalled that his maternal grandfather, a Londoner, opened his mind to the richness of language and stocked his memory with the turbulent history of the south Wales coalfield, both of which strongly influenced his early development. He was educated at Pontypridd grammar school and Aberystwyth University, where he studied French.

He met Ruth Meredith in the 1960s, when they were both party activists on behalf of Plaid Cymru. Marriage to Ruth, whose family came from Llanuwchllyn in north Wales, invested Meic with ties of kinship and friendship to a large circle of people prominent in Welsh life. He had begun to learn Welsh while at university and was already fluent. It became the language of his home and family: a crowd of his grandchildren swelled the number of Welsh speakers recorded at the last census.

In 1990 he left the Welsh Arts Council (which has since been renamed the Arts Council of Wales) to go freelance. He had an enormous appetite for work, whether as poet or journalist, encyclopedist or translator, editor or prolific obituarist for the Independent. In 1994 he joined the staff of the University of Glamorgan, established on a campus a stone’s throw from his birthplace. Within a few years he became professor of Welsh writing in English, a post he held until 2005.

In retirement he continued to find major literary projects and to work at them as indefatigably as ever. In 2014 he won the Wales Book of the Year prize with Rhys Davies: A Writer’s Life, his biography of the Welsh novelist and short story writer. In 2015, his autobiography, My Shoulder to the Wheel, appeared, and in 2017 The Old Red Tongue (co-edited with Gwyn Griffiths), a monumental anthology of Welsh literature.

He is survived by Ruth and their children, Lowri, Heledd, Brengain and Huw, and 11 grandchildren.

• Meic Stephens, writer, editor, arts administrator and academic, born 23 July 1938; died 2 July 2018