Here’s a tricky question. Who’s the most influential historian since the Second World War?

Some readers might pick the French scholar Fernand Braudel, whose groundbreaking work on the Mediterranean world encouraged generations of scholars to think about the longue durée. Many Anglophone readers, especially on the left, might think of E. P. Thompson, whose classic work The Making of the English Working Class championed the ordinary people who had so often been left out of Whiggish political histories. And no doubt there would be plenty of votes for another grand old Marxist, Eric Hobsbawm, whose histories of the modern age won legions of disciples from India to Brazil.

But from a British perspective, at least, the most obvious candidate is never mentioned. His name was R. J. Unstead, and in his heyday, between the 1950s and 1980s, his influence was simply enormous. Unstead published so many books that it’s hard to keep count, on everything from the Assyrians to world wars, and sold millions upon millions of books. His most successful title, almost incredibly, shifted an estimated eight million copies. Year after year, his words established an imaginative foothold that none of his rivals could match. But nobody ever talks about him today, for a reason that is obvious: he wrote for children.

These days Unstead’s books are out of print, but to anybody British who grew up between the Suez Crisis and the fall of Margaret Thatcher, his name will be immediately familiar. Every school boasted copies of his books; so did millions of children’s bedrooms.

What were they like? You may not find them in bookshops today, but his Years of the Sword, published in 1972, is beside me right now. It’s billed as a pictorial history of England between 1300 and 1485, but it’s much more than that. For me, even the section titles – ‘The Hundred Years War Begins,’ ‘The Odds Against Death,’ ‘The Rule of a Tyrant,’ ‘The Battle for England’ – are little literary madeleines, catapulting me back to a classroom in the Midlands, some time in the early 1980s.

For a history-crazed small boy, Years of the Sword was an utterly absorbing read. A detailed diagram of the Battle of Bannockburn shows exactly where it all went right for Robert the Bruce and wrong for Edward II. A few pages later, there is a section entitled ‘Deadly Weapons,’ with a lot of pictures of maces. There’s a picture of a doctor sticking a sinister-looking device into a man’s bleeding leg. There are plenty of pithy, memorable judgements. ‘In his last years, influenced by an evil mistress, he became a feeble old dotard,’ Unstead says curtly of Edward III. And there are enough flashes of drama to keep the most impatient reader happy: ‘Richard submitted to the murderous bullies, but he did not forget. The day would come when it would be his turn and, for that day, he brooded and waited…’

Given Unstead’s gigantic popularity –it is worth repeating that his most popular book sold eight million copies – it is odd that he is now so completely forgotten. A couple of years ago, starting work on my own series of history books for children, Adventures in Time, I looked him up and was astonished to find that, online at least, it’s as if he never existed. Google H. E. Marshall, who wrote the Edwardian history book Our Island Story, and you find plenty of articles, for and against. But Unstead, who lived more than half a century later, and whose words were read and absorbed by almost every child in the land, has virtually disappeared.

But perhaps that’s not so surprising, since Unstead’s life was hardly the stuff of a Hollywood biopic. Fittingly for a writer who taught millions of children about English history, he was the epitome of Home Counties respectability. He was born in Deal, Kent, in 1915, the son of a Post Office clerk. According to Professor G. R. Batho’s profile of him in the Oxford Dictionary of National Biography, he fell in love with history at the age of nine, when he won the East Kent Wolf Cubs’ prize for an essay on the British Empire. As a grammar-school boy he won a scholarship to Cambridge but could not afford to take it up – a tragically common story in those days.

Undeterred, Unstead trained as a schoolteacher, fell in love with a chemist’s assistant called Florence and sold two short stories to an evening paper so he could buy her an engagement ring. They married and had three daughters. War came, and Unstead became an RAF sector controller, supervising operations in Normandy, Greece and Italy. Afterwards he became headmaster of a school in Letchworth, Hertfordshire – the world’s first garden city, a kind of social and architectural testament to the more optimistic side of the twentieth century.

What was Unstead like? Batho describes him as ‘a modest and humorous man,’ marked by ‘a boyish enthusiasm as well as an outspokenness which marked him as an honest man and a sincere friend.’ He was a keen golfer, gardener and cricket fan. But he was ‘above all a family man,’ devoted to his daughters. He died of heart failure in 1988, having sold more books than any historical writer of his generation. And that was that.

The remarkable thing about this is its sheer unremarkability. There are hints of a road not taken: we are told that Unstead ‘accepted philosophically that his early ambition to become a high-flown literary critic and novelist was not to be fulfilled.’ But in many ways this could be the life of any quiet, decent, respectable schoolteacher in twentieth-century Britain, all the way down to the good war and the gardening.

Perhaps that’s the point, though. Unstead’s heyday came at a time when the historical profession was in a state of flux, the old guard challenged by the rise of feminism, post-modernism and ‘history from below.’ But as you might expect from a Home Counties headmaster, he disdained iconoclasm for its own sake, and always put the child reader first. His books never lecture or talk down to the reader, as Our Island Story often does. Their tone is measured, thoughtful, friendly but authoritative: the tone of a father of three who watches cricket and plays golf.

Even in Unstead’s own time, there were those who shook their heads at his success. In 1980 a rival children’s historian, Sallie Purkis – perhaps not coincidentally, a lifelong Labour activist – issued a broadside in Teaching History, urging teachers to ditch his books. Unstead’s three sins, she explained, were that he believed history was the story of great men, that he used history to promote moral values and that he upheld a conservative Englishman’s vision of the world. He was, in short, the ‘Unacceptable Face of History.’

That’s a pretty harsh thing to say about anybody, not least because it was completely wrong. Take Unstead’s most successful book, Looking at History, originally published in 1955, which covers the entire story of England from start to finish. On the first page, he warns that there is ‘not [going to be] much about kings, queens, battles and politics, only just enough to let you know who were the rulers and what were the chief events at the time when, say, people, lived on the manor or rode in stage coaches.’ He’s true to his word, for by the standards of the 1950s his book is a social historian’s dream. There’s an awful lot, for instance, about medieval toilets, archery, cock-fighting, bear gardens, smugglers, three-cornered hats, cricket, executions, hunting, railways, cars and aeroplanes, with all sorts of facts and colour. But kings, queens and politicians come and go in a flash.

What about the conservative Englishness? Well, his book is certainly very English. In the index there are as many entries for schools as for Scotland, and almost as many for sedan chairs. Samuel Pepys has three times as many entries as the whole of Wales, and gardens are mentioned more often than Ireland. And there’s no doubt that Unstead was patriotic. ‘At a time when it is fashionable in some quarters to belittle England’s achievements in the past and to doubt her place in the future,’ he wrote, ‘I have tried to show that whereas England has often acted foolishly or badly, her history shows the persistence of ideals which good men have lived by since Alfred’s day.’

No doubt some people would shudder at that today. They would probably be similarly appalled by Unstead’s remark, in a lecture in 1985, that he ‘wanted children to begin to understand that the past was different from the present and that it is unfair to judge people of the past by the standards and ideas of today.’ To me, however, both those remarks seem perfectly reasonable. Indeed, they strike me as precisely the attitudes you want from somebody writing history books for English children, whether in the 1950s or the 2020s.

I’ve been thinking a lot about Unstead in recent months, often dipping into his books for inspiration while writing my own Adventures in Time. Of course books like Looking at History seem a bit dated today. No writer in 2021 would mention slavery only in passing, for example. But criticising him for being a man of the 1950s seems utterly pointless. His books seem dated, because all books date.

What haven’t dated, though, are Unstead’s virtues: directness, candour, compassion. He knows how to tell a story, and he knows what children like: lots of details about brutal weapons and weird medicines, strange hats and exotic foods. His books aren’t Horrible Histories, though: he never plays the past for laughs. He takes it seriously and tells it simply. The more I think about it, the more puzzled I am that Unstead’s books are out of print. Any child who made it all the way through Looking at History would know more about England’s past than the vast majority of adults today.

‘Despite all the important changes and advances that have been made in history teaching in the past two decades, and despite all the names which have been made through them, not one single writer of children’s history has yet even approached the eminence or creative productivity, never mind the affectionate esteem, which were the hallmarks of R. J. Unstead.’

The historian Sean Lang wrote those words in 1990, two years after Unstead’s death, when I was still at school. He was quite right. And he would be right if he wrote the same thing today, too.