How Max Mosley's remarkable childhood formed the man 

Reading the many obituaries of Max Mosley, who died this week aged 81, is to be confronted with a dizzying array of superlatives, often contradictory: fiercely intelligent, Machiavellian, determined, authoritative, amoral.

Depending on which paper you read, Mosley was “one of the most influential and important figures in motorsport”, “a brilliant but flawed figure”, one whose career as president of Formula 1 helped him “emerge from the shadow” of his father, leader of the British Union of Fascists in the 1930s, Sir Oswald Mosley.

Not that motor racing was his only achievement: he was the principal force behind global standards for road safety, potentially saving the lives of millions.

But after it emerged in 2008 that he had hired prostitutes to engage in sado-masochistic orgies, he dedicated the rest of his life trying to tighten privacy laws and, as the Telegraph noted, “spent millions trying to stop stories appearing in the press”.

My own particular interest in Mosley comes from his parentage – not, for a change, his fascist father, whose racist rallies stoked civil unrest during the 1930s. Rather, my interest is more Max’s mother. My series of detective stories, the Mitford Murders, is set amid the legendary Mitford household, with each book featuring one of the six fascinating, famous Mitford sisters.

Mosely was the youngest son of Diana Mitford, a society beauty, who was only 22 years old when she left her husband Bryan Guinness – “the nicest man in London” – for Sir Oswald, a man who was known to be a cad.

Sir Oswald was also married, to Lady Cynthia Curzon, but admitted to her one night that he had had numerous affairs. On hearing the long list of names, Lady Cynthia is said to have replied faintly: “But they’re all my best friends…” Within days, her health had deteriorated to such a degree that she collapsed with appendicitis, followed by peritonitis, and died.

The summer after her death, Sir Oswald went on a touring holiday around France with his late wife’s sister, Baba Metcalfe. When Baba’s husband complained, he was told by the Curzon family to be more sympathetic to his brother-in-law’s needs. During his marriage to Lady Cynthia, Sir Oswald had also had an affair with the third sister, Irene, as well as their stepmother. He was not a man one would have called a safe bet.

When Mosely, their youngest son, was born, it preceded what was a turning point in his parents’ life. He was 11 weeks old and not yet weaned when Diana was imprisoned in 1940 under the Emergency Powers Bill that had been rushed through after war began. Even after her arrest there were no charges and no trial. Sir Oswald had entered Brixton prison only weeks before under the same bill. Diana had been shopped as a traitor to the country for her political beliefs by her former father-in-law, Lord Moyne, as well as by her sister, Nancy (author of ‘Pursuit of Love’).

Perhaps they had a point: Sir Oswald was the founder of a far-Right political party whose protests were so violent and nasty, they led to the Public Order Act banning military-style uniforms and mass gatherings after he marched through Jewish neighbourhoods in the East End.

For her part, Diana had spent a lot of time in Germany, attending Nuremberg rallies and befriending Adolf Hitler. And then there was the small matter of Diana and Sir Oswald’s 1936 marriage in Joseph Goebbels’s ministerial drawing room, with Hitler as a witness.

When she and Sir Osward were imprisoned in 1940, Max and his brother, Alexander, still both babies, were unable to live with their grandmother, Lady Redesdale, as she was fully occupied caring for her brain-damaged daughter, Unity, after she had attempted suicide on the outbreak of war, torn by her love for her country and for Hitler, with whom she was obsessed.

Instead, the boys were sent to live with their aunt Pamela, the most stalwart and least maternal of the six Mitford sisters. For most of the war, Diana’s four boys (she had had two with Guinness) were either at boarding school or cared for by nannies, with occasional visits to see her in Holloway prison.

These trips were quite a trek from Oxfordshire to London under the constant threat of air raids. Diana stopped the visits after a while, finding the distress they all suffered saying goodbye at the end of their time together – often as little as 15 minutes – was harder to bear than the long-term separation.

In some ways, this distance from their parents was not so unusual for an aristocratic household, but for the fact that Diana was an unusually loving mother for her class. When her eldest boys, Jonathan and Desmond Guinness, were first born, she was heard to long for the nanny to have the day off so that she could spend time with them.

From having been one of London society’s bright young things, rich and beautiful when she was married to Guinness, Diana after the war was a social pariah. Her family and many of her former friends were horrified by her marriage to Sir Oswald and her continuing defence of Hitler. As late as 1989, in an interview for Radio 4’s Desert Island Discs, she still maintained that she admired Hitler “very much”, and that she thought the number of Jews exterminated by the Nazis had been exaggerated: “I don’t really believe it was six million people – it’s just not conceivable.”

Her obstinacy in her refusal to adjust her views led to a virtual exile, with her and Sir Oswald largely living in France for the rest of their lives, befriending other high-society rejects such as the Duke and Duchess of Windsor.

Once, it had all been so promising. Sir Oswald began a political career as a Conservative MP before crossing the floor to join the Labour Party which had recently formed the government, and was briefly touted as a potential leader. But when they would not accept his radical economic policies, he resigned his ministerial position and soon formed the British Union of Fascists in 1932, just as he met Diana. She could never admit she had made a mistake in giving up all of society to love this man.

It is clear to see where Mosley got his obstinate and determined nature from. He must have needed it as a young boy at school in England – with two years in Germany to learn the language – and then at Oxford. The Mosley surname would have proven a heavy burden in the post-war years.

He learned, I think, not to care what other people thought; certainly not so long as he believed he was pursuing something for the greater good. Part of this was his strong belief that individuals reserved the right to pursue private passions without public judgement. Perhaps from his father he inherited a certain ability to divide spousal devotion from sexual needs.

Mosely was close to his father, even at one time attempting to follow him down his political path. But I think the most telling anecdote about him was that when he first went into motor racing as an amateur driver, he overheard someone say that they thought he must be related to Alf Mosely, the coach builder. Thrilled to have found a corner of the world where no one had heard of his father, that was where he remained.

Jessica Fellowes is author of the ‘Mitford Murders’ series, each starring members of the Mitford family. See books.telegraph.co.uk