Tens of millions of people are alive today who would otherwise be dead had Richard Doll not made his enduring contribution to medical science.

This is the one simple, monumentally significant fact that is widely known about the great Oxford scientist, who first linked smoking with cancer.

Now, four years after his death, an official biography offers the world the chance to learn something more about a complex man who was both loved and feared during a career in research that only ended with his death, aged 92.

The story of how Doll jettisoned his establishment background to become a Communist Party member who treated the blistered feet of the Jarrow marchers, shows the natural patrician in a new light as a political revolutionary.

As the great prophet of one of the last century’s most uncomfortable truths, he was initially vilified and subjected to bitter attacks from far beyond the tobacco industry. And even friends and ex-colleagues of the great man will be shocked to learn that, as his life neared its end, he had asked the Oxford GP Ann McPherson and Oliver Ormerod, a consultant cardiologist at the John Radcliffe Hospital, to suspend their Hippocratic oaths and expedite his death — a request that was refused.

The revealing new portrait of a private figure who towered over 20th-century public health is offered to us by Conrad Keating, writer in residence at the Wellcome Unit for the History of Medicine in Oxford.

Some of those attending the book’s launch at Green Templeton College on November 11 may want to reappraise their opinions about a man whose ability to camouflage his emotions made Keating’s task far harder than the writer had anticipated.

They first met in the late 1990s, when Keating was researching a programme for the BBC. It was to be a memorable first encounter.

“The first time I met Richard Doll, he cried,” recalls Keating. “It was not because he had just discovered how little I knew about medicine. Rather, it was an emotional response to the memory of what he had seen on the Jarrow Hunger March, over 60 years before, when, at first hand, he experienced the waste and despair of the 1930s.

“Any history of modern Britain should contain something of Doll’s life. When I put to him the idea of me writing a biography, he agreed, as long as he did not get to see it. He wanted a warts-and-all biography. I suspect there are things in the book that he hoped I wasn’t going to find out.

“Doll was not an enigma. Yet, while his friends described him as ‘gentle and kind’, his emotional detachment and what some perceived as his ‘unconscious intimidation’ led to him being both feared and respected.”

Over five years the pair met regularly, with Keating even joining Sir Richard on trips abroad.

“We often went to the cinema together. He loved Tolkien. I remember going with him to see Lord of the Rings. At the end he turned to me and said, ‘this is almost like being friends’. But I always felt I had to be careful around him. He did not like sloppy thinking. He just didn’t have the time for it.”

The book is entitled Smoking Kills: The Revolutionary Life of Richard Doll, in recognition of the fact that smoking forms the main thread of Richard Doll’s story as a scientist.

The research paper that concluded that smoking cigarettes was “a cause and an important cause” of lung cancer appeared as early as September 1950, a time when British men had the highest lung cancer rates in the world. It was an era when 80 per cent of men smoked and it was not uncommon for doctors to offer patients a cigarette as they took a seat in the surgery. The study, produced with his great mentor, Sir Austin Bradford Hill, was, however, greeted with a combination of apathy, disbelief and scientific condemnation. It was not accepted by most other medical scientists, including those on the Ministry of Health’s standing advisory committee on cancer and radiotherapy, while the tobacco industry’s attempts to discredit Doll’s findings were helped by the media’s lack of interest in the discovery.

The media baron Lord Beaverbrook even instructed his journalists not to write articles about cancer, seeing it as an unpalatable subject for his readership.

But then, as Sir Richard admitted in an interview in The Oxford Times, even he had not initially viewed tobacco as the likely cause of the growing death toll. Car fumes were initially suspected.

“I actually thought the rise in lung cancer was something to do with the tar on the road,” he told me.

Sir Richard had smoked both pipes and cigarettes in the army, with whom he saw service as a medical officer at the Dunkirk retreat. His father in the First World War had seen at first hand the acceptance of cigarette smoking in the army. Regarding it as a waste of money, Richard was promised £50 on his 21st birthday if he succeeded in resisting the temptation to smoke.

Sadly, his younger brother’s taunts about the reward led to Doll, for once bending to abuse, taking up smoking at 17.

While his father was a physician, his mother, Amy Kathleen May Doll, was a famous classical pianist. The family had a chauffeur and lived in Knightsbridge. Sir Richard would recall getting in trouble as a youngster for playing games with ‘street children’.

He was recognised as the most outstanding mathematician at Westminster School. And while still a schoolboy he joined the Young Communist League of Great Britain, believing it to offer the only solution to mass unemployment. He was to remain an active communist until 1957 and, in Keating’s view, Doll’s career suffered from “the allergic response” of the conservative medical hierarchy to his left-wing beliefs.

Even in Oxford decades later, his communism was remembered. When he established Green College in 1979, to provide for the needs of clinical medical students, the new institution was dubbed by his enemies as “the Kremlin on the Woodstock Road”.

Earlier, when it emerged that Sir Richard and his wife, Joan, could not have children, he had asked his then boss to write a letter supporting their application to adopt. Bradford Hill apparently thought for a moment and then told him, ‘I don’t think communists should have children — it wouldn’t be right.’.”

The traumatic experience of adopting led the Dolls to set up the Agnostic Adoption Society, in a bid to stop the suitability of prospective adopting parents being judged on the basis of their religious affiliations.

Similar tenacity and moral integrity were needed in what was to become a lifelong battle with tobacco industry, big business and the uninformed. His response to the initial equivocation of the medical profession to his watershed discovery was to embark on a study that was to last 50 years, proving beyond doubt that tobacco leads to lung cancer, heart disease and other serious illness.

In 1951, he began an investigation into the smoking habits of 40,000 doctors. Long before the time he brought it to an end in 2001, he had developed a whole new approach to epidemiological inquiry.

In the process, Oxford was established as a world centre for epidemiological research, with Doll’s great scientific protege Sir Richard Peto and Prof Rory Collins continuing to lead major large-scale studies of the causes, prevention and treatment of heart attacks, vascular disease and cancer.

The two men were among the Oxford scientists to defend the Doll legacy when articles appeared after his death suggesting Sir Richard had failed to disclose payments from a chemical company. The assault on Doll’s reputation centred on allegations that he was paid a consultancy fee of $1,500 a day in the mid-1980s from Monsanto.

Attention was drawn to a letter Sir Richard had written to a commission investigating the properties of Agent Orange to say there was no evidence that the Monsanto-made chemical caused cancer.

Keating says he is satisfied that Doll never hid his relationship with industry, but was careful to record all his dealings, with the documents now deposited in his archive at the Wellcome Trust Library.

As for the Monsanto money, it was handed to charity.

“Doll’s reputation was built on integrity,” argues Keating. “Nowadays medical publications have to include disclosure statements about sources of funding, but this was not the standard practice in the 1970s and 1980s. Doll approved wholeheartedly of its introduction.”

Doll, of course, was no longer around to defend himself. He suffered a heart attack in 2005. But why had he asked his two friends to take his life?

“He strongly believed that it was wrong to spend large sums of money trying to keep an old person alive for a few months when, by spending less money, a young person could be kept alive for 50 years,” argues Keating, who is to mark the end of a decade ‘living’ with Doll by flying out to Nairobi to undertake research on his next book, which will be on malariologists.

He offers a final memory of the man who changed the health of a nation.

“The last time I saw Richard Doll was the first time his exemplary good manners failed him. It was the last week of his life. While I was reading through the mass of cards and letters from well-wishers that covered his hospital bedside locker, he looked at me and said, ‘what are you looking for now? You’re always digging around my life.’ But I had to do the digging. He would have respected me less if I had not.”