He was unusual among academic historians in that, although meticulous in his scholarship and widely read in the history of Marxism in Europe, he was able to infuse his writing with a passionate concern about the fate of his own people and to demonstrate, often in a most vivid manner, that Wales - particularly South Wales - was the very anvil on which the progress of the urban working class had first been hammered out.
But he was not content with scholarly exegesis that was not backed up by political engagement. He tried to influence public opinion by presenting the history of Wales in new, sometimes startlingly dramatic ways, whether in his lectures and books or in the many television programmes he made, in both Welsh and English, during the latter part of his career. In all his work the call to action was explicit and unequivocal: the capitalist, centralist, British State (and the English hegemony) had to be undone if the national community of Wales was to survive and prosper.
Although he began, during the heady days of the civil war in Spain, as a Young Communist, and remained an unrepentant Socialist for the rest of his life, Gwyn Alf (as he was known, to distinguish him from several other eminent Welshmen with similar names) was for many years an uneasy member of the Labour Party but eventually found his political home on the left wing of Plaid Cymru. For a while he was a leading member of the editorial board of the magazine Radical Wales, and served on the party's Executive Committee. He was, however, never persuaded to stand as a Plaid Cymru candidate, although his oratory (in which he used a slight stammer to excellent effect) made him one of the most effective and popular public speakers in Wales.
Born in the iron town of Dowlais, on the hill above Merthyr Tydfil, the cradle of the Industrial Revolution in Wales, Williams read History at the University College of Wales, Aberystwyth, and was appointed Lecturer in Welsh History there in 1954. He was such an entertaining speaker that students from other departments, myself among them, regularly sat in on his lectures, for the sheer excitement of hearing what he had to say about the industrial Wales in which we had grown up, after which we adjourned to the nearest pub, where he would continue to hold forth with the most brilliant dialectic that any of us had encountered.
Williams left Aberystwyth to take up a Readership at York and from 1965 to 1974 he held the Chair of History at that university. His doctoral thesis had been published as Medieval London: from commune to capital, in 1963, and was followed five years later by Artisans and Sans-Culottes, about popular movements in France and Britain during the French Revolution. His European perspective was grounded in these early works and others: Proletarian Order (1975), a study of Antonio Gramsci and the history of Communism in Italy, and Goya and the Impossible Revolution (1976), as part of the research for which he learnt Italian and Spanish respectively. His wife, Maria, belonged to the community of steelworkers from northern Spain who were long established in Dowlais.
But it was with his books on specifically Welsh subjects that Williams made most impact as an historian. Returning to Wales in 1974 as Professor of History at University College, Cardiff, he set about re-interpreting key episodes in Welsh history. His The Merthyr Rising (1978) was the first full account of the workers' revolt of 1831 and the execution of Dic Penderyn, one of the earliest martyrs of the Welsh working class.
In Madoc: the making of a myth (1979) he examined the evidence for the discovery of America by Prince Madog ab Owain Gwynedd in about 1170 and, in particular, for the existence of a tribe of Indians, known as Mandans, who were said to be his descendants. It was the Welshman John Dee, the magus of his age, who had first claimed the New World for the Queen of England on the basis of this persistent yarn, which was developed by Robert Southey in his long poem Madoc in 1805. Williams debunked the myth as an imperialist fiction, but showed how it had fired the imagination of Welsh Radicals for centuries thereafter and was comparable, in its patriotic potency, with the English myth of the free-born Saxon living under the Norman yoke.
He returned to these themes and introduced others in The Welsh in their History (1982), a collection of essays which argues for the opening up of new discourses, and in When was Wales? (1985), perhaps his most influential work. The latter was written while he was making the television series The Dragon has Two Tongues, in which he appeared in bruising confrontation with the rather more cautious Wynford Vaughan-Thomas; the question of who won this verbal punch-up, and on how many points, is still hotly debated in Wales and one by which the sheep and the goats can be separated.
The book concludes with some typically trenchant observations, not unaffected by the stress of Thatcherism:
The Welsh as a people have lived by making and remaking themselves in generation after generation, usually against the odds, usually within a British context. Wales is an artefact which the Welsh produce. If they want to. It requires an act of choice. Today, it looks as though that choice will be more difficult than ever before. There are roads out towards survival as a people, but they are long and hard and demand sacrifice and are at present unthinkable to most of the Welsh . . . Some kind of human society, though God knows what kind, will no doubt go on occupying these two western peninsulas of Britain, but that people, who are my people and no mean people, who have for a millennium and a half lived in them as a Welsh people, are now nothing but a naked people under an acid rain.
In 1983 Williams took early retirement from his Chair at Cardiff (he was fond of describing himself as "a redundant historian") and began making films with Teliesyn, one of the independent companies on which the reputation of Welsh broadcasting now largely depends. He moved from Cardiff to the village of Drefach Felindre, in Dyfed, where he shared a home with Sian Lloyd. Among the people about whom he made films were James Gillray, Sylvia Pankhurst, Pushkin, Mary Shelley, and the Welsh writers Saunders Lewis, T.E. Nicholas and Iolo Morganwg.
His last book, Excalibur: the search for Arthur (1994), was a clear-eyed account of a subject which has confused so many lesser historians, and his last film, Gwyn Alf - a People's Remembrancer (1995) a moving autobiography of a man who chose the hard road to an understanding of his life and times.
The image of Gwyn Williams which remains in the memory contains his pugnacious but engaging manner and the impish wit with which he expounded his theses about Wales and the Welsh. A small man, with a shock of white hair and the Iberian features that seem so typical of the valleys of south-east Wales, he developed a quirky but compulsive television style that had all the immediacy and eloquence of his writing, using the medium unapologetically to put over what he thought the Welsh people needed to know about their own past.
But I am pretty sure that it is his books that he will be remembered. For many of my generation, who were undergraduates in the late Fifties and early Sixties, and who participated with him in the political campaigns of the Seventies and Eighties, he shares a place with that other great Welsh Socialist, Raymond Williams, as an important influence on the way we now think about our country and people.
Gwyn Alfred Williams, historian: born Dowlais, Merthyr Tydfil 30 September 1925; Professor of History, York University 1965-74; Professor of History, University College, Cardiff 1974-83; married 1950 Maria Fernandez (one son); died Drefach Felindre, Dyfed 16 November 1995.