Welsh author, poet, and historian most well known for his work documenting Welsh literary history.
He grew up speaking Welsh at home, but was educated in English. He began his career as a teacher in Cardiff.
He was given an award in 1971 by the Arts Council of Wales and was elected President of the Welsh Academy a few years later.
He married Phyllis Doreen Jones in 1935 and dedicated all of his books to her.
He was a longtime friend of the poet Dylan Thomas.