The son of a Methodist minister, he went to Kingswood School, Bath, going on to Magdalen College, Oxford, just before the Second World War. He then served five years in the Army as a telephone engineer before returning to Oxford. After taking the best degree of his year, he was encouraged by Professor G.D.H. Cole to study industrial relations. The subject appealed to his rebellious and egalitarian temperament.
He joined Nuffield College, then in its infancy, and became a Fellow in 1949. There he started a 20-year academic partnership with Alan Flanders, a pre-war trade-union activist whose later theoretical writings were to be highly influential. As well as running a legendary seminar series together, they edited The System of Industrial Relations in Great Britain (1953), which broke new ground in its far-ranging overview of collective bargaining. Meanwhile, Clegg wrote a succession of studies, of nationalised industries, employers' organisations, industrial democracy, and trade union officers, which explored the untidy institutional detail of industrial relations. He embarked upon the authoritative A History of British Trade Unions, of which the first volume was published in 1964; the second and third volumes had to wait for his retirement.
Industrial relations were, by the 1960s, becoming a source of national concern. Clegg's clear, retentive, and independent mind made him a natural candidate for the many boards of inquiry favoured for problem-solving in those more tolerant times. Through his work on the railways, the docks, shipping, and the car industry he earned respect as an incisive questioner who would boil down messy evidence into a lucid report.
Clegg was an obvious appointee to the Royal Commission on Trade Unions and Employers' Associations set up in 1965 by a Labour government seeking legislative solutions to the "strike problem". He ensured that an unprecedented programme of research was commissioned. Then, when the majority of the Commission appeared to be stumbling towards legal sanctions aimed at strikers, he drafted a powerful counter-report which won over the majority. Strikes, it argued, were a consequence of poor management, not of demonic shop stewards. Employers should recognise that the industrial agreements they had relied on should, in much of industry, give way to what would now be called enterprise bargaining. It was an analysis that politicians rejected but which subsequent events have overwhelmingly vindicated.
Clegg's time on the Royal Commission coincided with his being a founder member of the National Board for Prices and Incomes. There his lasting contribution was to insist on enquiry by case-study, marshalling an army of academic field-workers to explore, by talking to the men and women at the grass-roots, the grubby facts of labour management. He wrote the lessons up in a book characteristically entitled How to Run an Incomes Policy, and Why We Made Such a Mess of the Last One (1971). When, in 1979, James Callaghan persuaded him to settle the "Winter of Discontent" public service disputes by chairing the Commission on Pay Comparability, he followed up with a similarly thoughtful valedictory report which remains a remarkable analysis of public service pay policy.
He left Oxford in 1967 to become Professor of Industrial Relations at the new Warwick University. Among the mud and wooden huts he played a major part in creating what has become the most successful of Britain's post-war universities. Warwick's strength in social science and business studies owes much to the research environment he established; industrial relations grew rapidly as a part of this when the (then) Social Science Research Council set up its Industrial Relations Research Unit with him as Director, soon to be joined by Alan Flanders and George Bain. His graduate course in the subject remains internationally outstanding.
Two complete rewrites of what was now his own textbook were published in 1970 and 1979. He handed on the direction of the unit in 1974, and in 1979 retired from his chair to return to his History. Long into his retirement his bicycle kept him in close touch with his empire of enthusiastic researchers.
An almost truculently modest man, Clegg avoided the publicity that the circumstances of industrial conflict offered him. While forming close friendships with many of the employers and trade union officers with whom he worked, he mistrusted politicians. He won the devotion of generations of students and colleagues by the care and loyalty he gave to them. When his remorseless pencil had scarred an essay or manuscript beyond recognition, he was always ready to take the author off to the pub to restore their self-esteem.
As a scholar Clegg was accused of being obsessed with data to the neglect of theory. History will show the contrary. He was impatient of dataless theorising, but his own analyses - of industrial democracy, the role of management, bargaining structure, trade unionism - are incomparable. Political fashion and economic circumstances have battered collective bargaining beyond recognition in the years since Clegg retired. But when future generations seek to repair the excessive individualisation of working life, they will work with the understanding he has passed on.
Hugh Armstrong Clegg, industrial relations teacher: born 22 May 1920; Official Fellow, Nuffield College, Oxford, 1949-66 (Emeritus); Professor of Industrial Relations, Warwick University 1967-79; Chairman, Civil Service Arbitration Tribunal 1968-71; Chairman, Standing Commission on Pay Comparability 1979-80; married 1941 Matilda Shaw (two sons, two daughters); died 9 December 1995.