Laurence Sterne begins Tristram Shandy with an extensive and speculative account of the circumstances of his eponymous hero’s conception. I am tempted to do the same in this account of my discovery of History, but it is a temptation to be resisted.

The first of my father’s fifty-odd books was The Suez War, an early “instant book” but also a polemic against the Eden government, with an enthusiastic introduction by the darling of the Left, Aneurin Bevan. It bears the publication date 1957, but appeared within weeks of the cessation of hostilities in November 1956. My parents, who had been a couple but then fallen out for a while, were brought back together by the crisis. I — or, rather, what Sterne calls the Homunculus — was the upshot. By the time I was born the following year, in August 1957, they were married and indeed have remained so for 63 years. Given its formative role in my very existence, conceived as I was as a by-product of historical events, I feel obliged to give History, as a field of inquiry, a capital “H”. I don’t recall a time when History did not impinge on or, at times, take over my life. I started as a History Boy; I became a History Man; but I’m not ready to be history.

When in January 1965 news broke that Winston Churchill had died, I remember where I was — in church, at Mass — but not what I thought. Dim intimations of such earlier events notwithstanding, the first memory that was definitely not induced retrospectively was the Six Day War in June 1967. My father had ensured that we children were well-informed about the Middle East, but at the time I was on what was euphemistically called a school cruise. Our former troopship sailed to a fjord in Norway, then via Copenhagen through the Kiel Canal to Amsterdam. It was there, in a park, that our teacher Mr Major bought a newspaper and spread it out on the grass for us to read. In our absence, Israel had fought and won a famous victory against the combined forces of Egypt, Syria and Jordan. I devoured the news even more hungrily than my processed cheese sandwiches. This was History and we were, if not witnesses, at least contemporaries.

The taste of History still lingered when, some five years later, I was taken to stay for the weekend at Prescote Manor, the Oxfordshire farm presided over by Dick Crossman and his third wife, Anne. The farm had been inherited by Anne, who had worked among codebreakers at Bletchley Park during the war. Unknown to us, she had seen History at closer quarters than most.

But the dominant figure in the household was undoubtedly Dick. In the Wilson government he had been a pioneering Social Services Secretary, but is best remembered for his sensational and posthumously published Diaries of a Cabinet Minister, which broke the omertà of ministerial confidentiality and inspired the television satire Yes Minister. Now no longer a Cabinet minister, but my father’s successor as Editor of the New Statesman, Crossman clearly revelled in provoking the establishment. He had no inkling that the magazine’s board would, after only two years, unceremoniously sack him.

Journalists (and their children) mixed with politicians more easily in those days; I was introduced to the then Prime Minister, Harold Wilson, at a wedding reception in the House of Lords. But Crossman was the first that I saw at close quarters, in his own habitat. There was something of the autocrat of the breakfast table about this archetypal Wykehamist and Oxford don. In 1937 he had published Plato Today, which began as a series of BBC radio talks and took the philosopher to task for the use and abuse of his political thought, particularly by Nazis and Communists. A decade before Karl Popper’s postwar indictment in The Open Society and Its Enemies, what Crossman later called his “irreverent hostility” towards Plato had riled his older colleagues; his notoriety had helped to propel him into politics.  

Crossman’s Diaries blew away the last cobwebs from the corridors of power

The erudite stream of consciousness that flowed incessantly from this grand old man (he was actually only in his early sixties, about the age I am now) had a constant theme. History in the broadest sense — the history of ideas as well as events — was the only thing worth studying. 

This was inspiring for teenagers such as me, or indeed his son Patrick and daughter Virginia. Patrick was my age and we shared a love of war games: he had a large room where battles could be recreated, plus the forces with which to do it. Dick would put his head round the door and comment on the progress of the battle. Indeed, he clearly loved the geeky seriousness with which we took our tactics and strategy, lacing his comments with an impish sense of humour. When I met him, he seemed magnanimous, irrepressible, unforgettable. A few years later, Dick died of cancer, aged 66. For my friend Patrick, the loss of such a father was too much to bear. Not long afterwards, he committed suicide. 

From Dick Crossman, I learned two things. One was the absolute necessity of History to any deep understanding of politics. War may be, as Clausewitz says, the continuation of politics by other means. But war is also a kind of game; there are rules. Not so in politics, which merely has codes, enigmatic or entirely opaque unless correctly interpreted. History holds the key to these codes; historians are the codebreakers who can unlock them. 

The second lesson was the significance of documents for historians. The Crossman Diaries are the most important document of British politics in that era. Dick was not cut out to be an historian (unlike his daughter Virginia, who was), but he did provide the materials they needed. By insisting on their publication as soon as possible after his death, while most of the dramatis personae were still active in politics, he lifted the veil of deference towards the Establishment and blew away the last cobwebs from the corridors of power. Nothing quite like it has ever happened, before or since.

Where History was concerned, my background was a mixed blessing. My father’s decision in 1970, when he was in his early forties, to renounce the NS editorship to become an “historian in private practice” (as his fellow practitioner and friend Hugh Thomas put it) must have influenced my own adolescent passion for the subject. The thought of competing with him was daunting, however. The person who always encouraged me not to be intimidated by History was Antonia Fraser. I still have a copy of her second major biography, Cromwell: Our Chief of Men, with the flattering inscription: “For Daniel Johnson, another student of 17th century history, from his godmother Antonia Fraser, June 24 1975.” It is a happy thought that, 45 years later, Antonia and I are still talking about History and she is now entering her sixth decade of writing it. Her last book, The King and the Catholics, embraces all her favourite themes: the monarchy, Catholicism and human rights. To adapt one of her book titles, she is our Warrior Queen of History.

From our conversations Antonia had gleaned that I was gripped by my A-level special subject on the Civil War and Commonwealth. That was due above all to my history teacher at Langley Grammar, Mr Cheetham. He was a superb mentor: rigorous, enthusiastic and, in his own field, omniscient. What impressed me most, however, was that he treated me as an equal. I was invited to join him and one or two other teachers to listen to music during the lunch hour. I owe to him my appreciation of Mahler, whose Resurrection Symphony struck me at first as overblown Beethoven. Mr Cheetham gently rebuked me with the injunction to persist. 

As with Mahler, so with the Putney Debates. The thick volume of transcripts of this unique battle of ideas, fought out in the ranks of Cromwell’s victorious New Model Army in 1647, was my first encounter with historical documents. Mr Cheetham made us study them line by line, placing each utterance in context and bringing the speakers — officers and men, Grandees and Levellers — alive. The thrill of History is about the encounter with original documentary evidence, in whatever form, whatever the hermeneutics. 

I was almost moved to tears when, more than four decades later, I found myself with my eldest son and daughter-in-law in a debate at the same church in Putney. When I pointed out that we were on hallowed ground in the history of English democracy, one of the participants, Professor Lord Glasman, eagerly picked up the gauntlet. He is one of the few members of either house who thinks for himself. Unlike those such as Lord Adonis, who call for Cromwell’s statue in front of the Commons to be torn down on account of his alleged war crimes in Ireland, Maurice appreciates the Lord Protector, not least for readmitting the Jews to an England that had been judenfrei since 1290. Old Noll, the great Oliver himself, had also once sat in those pews, listening carefully but keeping his counsel. Perhaps he was the ancestor of Blue Labour: a social conservative and reluctant revolutionary.

My historiographical apprenticeship at Langley Grammar culminated in an application to read the subject at Oxford. I was the only one in my year to sit the then compulsory entrance examination. Realising that I needed specialised preparation which he could not provide, Mr Cheetham wangled me a place in Eton’s weekly Oxbridge evening class, given by college’s senior history master, Mr Evans. The latter kindly allowed me to join in, while the Etonians eyed me with suspicion. I later learned from one of them that they assumed this “grammar school kid” had been brought in to keep them on their toes. Though nothing could have been further from the truth, I realised what I was up against: the best education money could buy, plus a sense of entitlement that engendered supreme confidence. My father had insisted on me taking the exam a year early; the others already had A-levels behind them. As a callow and self-conscious 17-year-old, I shrank from these suave scholars in their tails and fancy silk waistcoats. Mr Evans, though, gave me to understand that I was just as good as any of his pupils. To my genuine astonishment, Magdalen College agreed with him, despite my gauche performance in the interview. I got in to read Modern History.