During World War II, in the midst of the Liverpool Blitz, Williams served in a Quaker relief unit, having been a conscientious objector as both a pacifist and a Welsh nationalist.
Williams later moved from his ministry to accept a post at Granada Television in Manchester, presenting Welsh language programmes, in which his skills as a communicator came to the fore.
Of all Williams' work, his trilogy Cwm Hiraeth is seen by many as his finest achievement;[6] semi-autobiographical, the three books form a prose epic of life in the depression hit Rhondda through the eyes of the author's Uncle Sion, a poet and thinker.
In the 1970s, Williams and his family lived in a council house at Coed yr Haf, in Ystrad Mynach, where he continued to be an active member of the Welsh political party Plaid Cymru.
Nonetheless, despite his health, he continued to actively write and publish new material, serving an editor of Barn, a Welsh-language current affairs magazine, from 1980 until 1985.