In the spring of 1997, shortly before Tony Blair took power, William Rees-Mogg, ex-editor of the Times, leading Eurosceptic, pinstriped self-publicist and father of Jacob, published a book that claimed to see the future of the world. The Sovereign Individual: The Coming Economic Revolution and How to Survive and Prosper in It opened with a quote from Tom Stoppard’s play Arcadia: “The future is disorder.”

For 380 breathless pages, Lord Rees-Mogg and a co-author, James Dale Davidson, an American investment guru and conservative propagandist, predicted that digital technology would make the world hugely more competitive, unequal and unstable. Societies would splinter. Taxes would be evaded. Government would gradually wither away. “By 2010 or thereabouts,” they wrote, welfare states “will simply become unfinanceable”. In such a harsh world, only the most talented, self-reliant, technologically adept person – “the sovereign individual” – would thrive.

The book’s mixture of gloom and glee, and air of patrician certainty, did not go down well with British reviewers. In 1997, the west was entering a period of relative prosperity, equality and political optimism, which the rise of Blair personified. The book seemed too apocalyptic. Besides, Rees-Mogg had been making melodramatic predictions in newspaper columns for decades. So many had been wrong – Colin Powell would be the first black president of the United States; Margaret Thatcher would survive the 1990 coup against her – that Private Eye called him “Mystic Mogg”, after the astrologer Mystic Meg.

In August, Alastair Campbell called The Sovereign Individual 'the most important book you have never heard of'

When he died in 2012, the obituaries were more respectful, concentrating instead on his many years smoothly ascending and serving the establishment. They only briefly mentioned The Sovereign Individual, and the handful of other, equally strange and ambitious Rees-Mogg volumes that preceded it, without making much effort to explain what the books were about. His career as an author, the obituarists discreetly implied, had been an insignificant sideline, or a bit of an embarrassment.

That verdict is now beginning to seem premature. In August, Alastair Campbell, Blair’s former right-hand man and a prominent remainer, wrote about The Sovereign Individual at length on his blog. He called it “the most important book you have never heard of”. “After reading it,” he intriguingly claimed, “it is easy to see” why Jacob “so loves Brexit, and the chaos and disorder, and opportunities for disaster capitalism and super-elitism, that it may provide.”

Play Video 3:15 Will the real Jacob Rees-Mogg please stand up? - video profile

Across the Atlantic, the book has become associated with another disruptive tendency in modern politics, the rightwing libertarians of Silicon Valley. From the start, the book was better received in the US, where futurology and polemics against the state are more mainstream genres. In 2011, almost a decade and a half after the book’s publication, Rees-Mogg was still being invited there to talk about it, to students at Stanford University, one of Silicon Valley’s prime recruiting grounds. In 2014, Peter Thiel, the intellectually restless, fiercely conservative co-founder of PayPal, told the business magazine Forbes that The Sovereign Individual had influenced him more than any other book.

As well as airy rhetoric about the internet’s revolutionary potential – already standard stuff for futurologists in the mid-90s – the book contained more concrete and pioneering predictions: about cryptocurrencies, electronic warfare, smartphones and the possibility of online bots imitating humans. Some of these forecasts had an accuracy that still amazes. Rees-Mogg and Davidson envisaged a “new digital form of money”, for example, to “consist of encrypted sequences … unique, anonymous and verifiable … tradable at a keystroke in a multitrillion-dollar wholesale market without borders” – Bitcoin in other words, a decade before it was actually invented.

Facebook Twitter Pinterest In today’s ever more connected, fragmented world, Mystic Mogg appears to be having the last laugh … William Rees-Mogg. Photograph: Eamonn McCabe/The Guardian

The book also foresaw a backlash against the footloose, cosmopolitan elites that digital technology would help create. The economy’s “losers”, as Rees-Mogg and Davidson called them, who “do not excel in problem-solving or possess globally marketable skills”, would turn to nationalism and bitter nostalgia. They would “seek to thwart the movement of capital and people across borders”.

In today’s ever more connected, ever more fragmented world, Mystic Mogg appears to be having the last laugh.

He was 68 when the book came out. The long, sometimes eccentric, rarely examined intellectual journey that led up to it tells us important things about transatlantic conservatism over the last half-century, and how drastically it has changed. Rees-Mogg’s journey also helps explain his increasingly powerful but still quite opaque son, Jacob: not just as a supporter of Brexit, but as an unsentimental and nimble “sovereign individual” of exactly the type his father envisaged. Simultaneously, Rees-Mogg Jr has managed to become a successful player in the modern, borderless financial industries, and a nationalist politician with an instantly recognisable retro image. He has seduced some Labour MPs with his old-fashioned manners; and he has met privately in a Mayfair hotel with the would-be guru of the international far right, Steve Bannon. This lack of squeamishness about how the conservative establishment holds on to political and economic power has been passed down the Rees-Mogg generations. As Jacob told the Times in 2015: “My father, with whom I discussed all aspects of politics and finance, was the greatest influence in my professional life.”

William Rees-Mogg was born in 1928. His father was a Somerset landowner, and his mother an American actor. From a young age William, like Jacob, combined fogeyishness – he loved double-breasted suits and old books – with a modern expertise at self-promotion. A high-profile undergraduate at Oxford, he told an interviewer from the student magazine Isis that he read the Financial Times every morning. He was hired by the paper shortly afterwards.

After failing twice to be elected as a Conservative MP in the 50s, he settled for achieving political influence by journalistic means, becoming editor of the Times in 1967, at the then precocious age of 39. Over his 14 years in the post, he grew steadily more rightwing. During the 60s, he was a relatively egalitarian Tory, arguing in a party pamphlet that “it is reasonable to encourage employees to identify themselves with a company by having some small share-holding in it” – an approach to capitalism being promoted by the shadow chancellor, John McDonnell. But by the mid-70s, the west’s postwar economic boom and political consensus were coming to an end, and Rees-Mogg joined the swelling ranks of rightwing doom-mongers. In 1974, he spent his August family holiday hastily writing a book, The Reigning Error: the Crisis of World Inflation.

Its tone was both grand and panicky. “Inflation is a disease of inordinacy,” he wrote. His readiness to generalise and use ostentatious, archaic language was something with which readers of his books – and followers of Jacob’s pronouncements – would become very familiar. “There are other such diseases,” Rees-Mogg continued, “anarchy and tyranny … cancer …” He argued that economic “order” could be restored by giving gold a central role in the world economy, a policy that had been out of fashion for decades. He also advocated monetarism, or restricting the supply of money: a newer idea that was becoming popular on the British right, and which would be adopted by Thatcher as premier – with mixed economic and devastating social consequences.

Rees-Mogg supported his arguments with a teetering pile of references from, among other fields, history, philosophy, psychoanalysis and nuclear physics. The overall effect was uneven: the fluent, entitled assertiveness of a Times leading article awkwardly mixed up with a more personal tone, digressive, a little amateurish.

Unlike his loquacious father, Jacob has the politician’s ability to say as little as possible when necessary

But Rees-Mogg was not put off. He was a confident, not especially conscientious newspaper editor, rarely in the office after 6.30pm. Three years further into his tenure, in 1977, he found the time to produce another sweeping book with a grandiose title: An Humbler Heaven, about his keen Roman Catholicism and the value of religion in general. Again, he was preoccupied by the need to bring order to a supposedly chaotic present. “A world which has lost its faith,” he wrote, “is like … a drowning man, desperately thrashing around.” Four years later, in 1981, he seemed to underline his opposition to the unruly forces of modernity by stepping down as Times editor shortly after Rupert Murdoch became proprietor.

Yet behind the showy Rees-Mogg reverence for rules and tradition there lurked more hard-nosed impulses. He had inherited money from his parents, and had always been interested in the stock market. After leaving the Times, he met Davidson by chance at the home of a mutual friend in Oxford. They quickly found that they agreed, Rees-Mogg wrote in his memoirs, on the importance of “low taxation” and “personal independence” from government – the two sacred causes of the radical right at the time and since. In 1983, the two men set up a company to publish a newsletter, Strategic Investment. It used their knowledge – or the knowledge they assumed they had – of history, business and social trends to offer long-term advice to wealthy investors. Rees-Mogg made each of his children a shareholder. Jacob was only just a teenager, but was already eagerly managing his own share portfolio, to the delight of the rightwing press.

In 1987, Davidson and Rees-Mogg expanded some of their newsletter material into a book, Blood in the Streets: Investment Profits in a World Gone Mad. Its main message was summed by a quote from the 19th-century financial trader Nathan Rothschild: “The best time to buy is when blood is running in the streets.” The book’s prose was equally blunt, broken up into bite-sized chunks, with grabby headings, as if to catch the attention of time-poor plutocrats. “The world is getting more dangerous by the day,” a typical sentence announced. Another advised: “You should probably hold some gold.”

In 1992, in a preface to another lurid Rees-Mogg and Davidson volume, The Great Reckoning: How the World Will Change Before the Year 2000, Rees-Mogg revealed that he had not, in fact, written either book. “My contribution,” he said, “has included … ideas … continued discussion between us … as well as the discovery of relevant books.” Since 1981, he had owned an antiquarian bookshop in London, Pickering & Chatto. Yet whatever his exact role in the collaborations – and judging by how many of his favourite historical figures and hobby horses appeared, it was substantial – his worldview had clearly shifted. Instead of warning against social and economic turmoil as a threat to conservatism and the well-off, he now saw it as an opportunity for them. After the millennium, many British and US rightwingers would follow him down that risky path.

Facebook Twitter Pinterest ‘I just want her to change one item of policy’ … Jacob Rees-Mogg on supporting Theresa May. Photograph: Daniel Leal-Olivas/AFP/Getty Images

Jacob is not much of a writer. He has produced no books. He is probably too busy with politics and his business career. But his father’s impact on his thinking and behaviour is obvious, once you know what to look for.

In 2012, two years after becoming an MP, he contributed a short, rather stiff introduction to an essay collection published by the rightwing thinktank Politeia. He wrote that he was for “the individual against the state”, and against a “society wrapped in cotton wool”. “The choice,” he concluded, is between “the collective and constant mediocrity”, and “freedom and great peaks of human endeavour” – a world arranged for personal success above all else.

In 1997, in The Sovereign Individual, Rees-Mogg Sr recommended Singapore to readers who were entrepreneurs, as one of several countries that “impose low costs” on business. The book also advised readers to use tax havens. In 2007, after studying history at Oxford like his father, Jacob co-founded Somerset Capital Management – the name a classic Rees-Mogg mixture of the cosy and the calculating – which has since become a highly profitable London company, investing money for clients in “emerging markets” such as south-east Asia. The company also operates from Singapore, and has a subsidiary in the Cayman Islands. Both are tax havens.

This summer, Somerset Capital opened two funds for investors in Ireland: only a few months after one of its prospectuses warned that investments in Britain may be “affected” by “considerable uncertainty” around Brexit – a possibility that, as a politician, Jacob always plays down. Accused of hypocrisy and unpatriotic behaviour, he insisted that these Irish ventures had “nothing whatsoever to do with Brexit”, and were simply a response to interest from clients.

Unlike his loquacious father, Jacob has the politician’s ability to say as little as possible when necessary, and thus close awkward issues down. He also has a sly way with threats and euphemisms that his incautious father did not possess. In September, amid rumours of an imminent leadership challenge to Theresa May, Jacob told the website PoliticsHome: “She is a fantastically dutiful prime minister and she has my support. I just want her to change one item of policy” – by which he meant her entire Brexit approach.

Two decades ago, The Sovereign Individual prophesied that in the 21st century, “many of the ablest people” would use “clearheaded cost-benefit analysis” to assess what was in their best interests. They would “cease to think of themselves as party to a nation”. That may be something for patriotic Brexit supporters – and the rest of us – to ponder if we get prime minister Rees-Mogg.