He was very much a historian with a period. His period was the 1770s and 1780s, and the political history of the reign of George III more generally. He produced a well-used textbook - Wars and Revolutions: Britain, 1760- 1815 (1982) - and a stream of monographs and learned articles on his period, out of which he was never tempted to stray, in 50 years of research, teaching and writing.
Once, at University College London in the 1970s, a short course of lectures on the main themes of modern British history was proposed. Peter Clarke (later professor of history at Cambridge) said he would lecture on class and on gender; I think I offered economic growth; Christie said he would talk about Lord Bute and about Lord North.
It was at University College London that Christie spent the whole of his post- Oxford career: he was appointed assistant lecturer in 1948, followed by lecturer and reader, before becoming professor of modern history by conferment of title in 1966 and finally Astor Professor of British History from 1979 until his retirement in 1984 - in succession to Joel Hurstfield (who had been Astor Professor of English History).
Christie was born in 1919 in Preston, Lancashire, though he spent his early years in Glasgow, and was certainly thought of as an Anglicized Scot. He was an invalid as a child and educated at home, later recovering to go to Worcester Royal Grammar School before going up to Oxford. His time as an undergraduate at Magdalen College, 1938-40 and 1946-48, was interrupted by war service as an RAF officer. As soon as he graduated he was appointed to the history department at UCL, snaffled up by the grand and tyrannical Sir John Neale.
In June 1948, as he was about to take schools at Oxford, Christie wrote to Neale after he had offered him the job: "Mr A.J.P. Taylor here has said he will procure me an introduction to Professor Namier in order that I may get advice on my proposed subject for research".
Thus Christie became a Namierite, sitting at the feet of that other grand and not untyrannical historian at the Institute of Historical Research, London University in the 1950s. Christie's first book, The End of North's Ministry, 1780-82 (1958), appeared as the second volume in Sir Lewis Namier's series, and Christie began his long association with the history of Parliament.
A respectable stream of articles and books followed, and Christie held office in the Royal Historical Society. At UCL he came to serve as chairman of the history department in 1975-79; earlier he had been dean of the faculty of arts, in the days when that office was decorative rather than managerial. In the demanding task of being head of department, he needed to be neither decorative nor managerial; he was wise, judicious, fair. Dare one think it was the good old days?
At all events, Christie's scholarly achievements were recognised: in 1977 he was elected Fellow of the British Academy and in 1983 he was invited to give the Ford Lectures at Oxford. The lectures, on why there was no revolution in Britain in the 1790s, were published as Stress and Stability in Late Eighteenth Century Britain (1984).
Christie's retirement speech at a dinner in his honour at UCL was memorable. He said that when he had joined the history department in 1948 there had been great men in it, and he was sure that one day there would be again. It caused quite a stir.
Although he appeared buttoned-up and conventional, Christie's views were often quite unpredictable. He was a sceptical rationalist, sometimes in a rather earnest Victorian manner. He once told me that he had become a historian because he wanted to understand why for centuries intelligent people had believed in Christianity.
He had a fascination for illness, sometimes legitimately channelled, as with his enthusiasm for discussing George III's porphyria, sometimes taking bizarre forms, as with his obsession about the medical records that supposedly revealed that Rudolf Hess was not the real Hess.
His first book was dedicated to his mother, and he was himself dedicated to his mother. When he was head of the department, meetings had to be rearranged so that he could always get home so his mother was not left alone after dark. He never stayed around chatting after a seminar at the Institute of Historical Research or after a meeting of the Royal Historical Society, as historians generally do; he went back to Croxley Green to be with his mother. She lived into ripe old age, and it was not until after her death, when Christie was in his seventies, that he permitted himself to marry.
Ann Hastings, his wife from 1992, was, like him, a keen member of the Croxley Green Tennis Club. His last years, until the last few months, were happy: his "recreations" in Who's Who evolved from "walking" to "gardening"; he beavered away, researching the history of his family and writing two unpublished volumes of autobiography, and earlier this year an article by him appeared in the English Historical Review that he could have begun nearly half a century ago.
Ian Ralph Christie, historian: born Preston, Lancashire 11 May 1919; Assistant Lecturer in History, University College London 1948-51, Lecturer 1951-1960, Reader 1960-66, Professor 1966-79, Dean of Arts 1971-73, Chairman, History Department 1975-79, Astor Professor of British History 1979-84; FBA 1977; married 1992 Ann Hastings; died Poole, Dorset 25 November 1998.