A humble Ladybird book started it all off. "It was by L Du Garde Peach," says Mark Bostridge with a smile. Given to him by his mother, it sparked a fascination with its subject, Florence Nightingale. "I think everybody of my generation in the Sixties was brought up on those amazing history books with the vivid pictures. I can still see the picture of her with the lamp, and the one of the soldiers marching off to the Crimea."
Ten years ago, when he first signed up with a publisher, he never suspected what a huge task his biography, Florence Nightingale: The woman and her legend, was going to be. "It's a real lesson that you should look into the practical problems. No sooner had I signed the contract, the British Library, which has 200 volumes of letters about Florence Nightingale's public life, immediately closed" [in preparation for its move to St Pancras]. Nightingale was one of the most indefatigable administrators and correspondents of the 19th century, and the archival labours alone were immense.
"Every time I looked at it, it just got more and more appalling, the scale of it. So for a long time it was a book I didn't want to write, and I decided that I wasn't going to." Access to the family archive at Claydon House, the home of Nightingale's sister Parthenope, reignited his passion. Nightingale had a vast extended family and their private papers were a treasure trove. By mining their depths diligently, Bostridge was able to put paid to many of the myths that have grown around the figure of the Lady with the Lamp.
What amazed me about reading his book, I say, is the revelation of Nightingale's astounding intellectual capabilities. "When I thought about doing the book, ages ago, I didn't realise she was this great intellect," Bostridge explains, "because like everybody else I had been brought up on the sentimental legend which thinks of her as a ministering angel and a nurse, and of course she was never a nurse, except in a very limited sense. She had a brief period in Germany before the Crimean War doing basic nursing training, and when she got to the Crimean War she did hardly any nursing at all, and never did any nursing subsequently. So to think of her as a nurse is such a ridiculous thing. What she was is a great nursing theoretician."
The range of young Florence's intellectual pursuits is awe-inspiring. A classicist and linguist, she was also keenly interested in theology and a gifted mathematician. "She was one of the most important statistical pioneers of the 19th century, and nobody knows that now. One of the greatest gifts she had, and this applies as much to nursing theory as it does to her later work in India, is that she could imagine herself in situations, and with a certain amount of statistical material, could work out solutions for things. She never visited India, and yet she had all these prescriptions for improving health and social conditions that were very far-reaching, and certainly ahead of their time."
At Claydon, bundles of letters, still tied up in pinky-red ribbon, had to be deciphered on the one day per month he was permitted to work there. "There were letters from practically every major writer or figure of the 19th century. It was wonderful to find unpublished letters from Mrs Gaskell, letters from Dickens, letters from everybody you could think of. Obviously you go through a lot of stuff. It's so tiring – you have to read so closely, this often horrifying handwriting and you feel you're probably the only person to have read these letters for 50 years. Suddenly, something springs out at you."
He recounts a story of working on the archive while a fellow Nightingale sleuth was reading documents in the same room. "I went to the loo, and when I came back she was poring over my notes. It's the biographer's nightmare!" he laughs.
He was able to scotch the tired old story of the rivalry between Nightingale and the Jamaican nurse, Mary Seacole. "I've tried to explain the reasons why Florence Nightingale wanted to distance herself from Mary Seacole, because of the reputation of Seacole's establishment for drinking. But in a letter from one of Florence Nightingale's aunts, it's clear that Nightingale gave money to Seacole when she was down on her luck after the Crimean War. It takes for ever going through these letters, but you find all these things you couldn't find any other way. So all this rubbish about the great hatred Florence Nightingale had for Mary Seacole, this stupid rivalry that people have posited, is just ridiculous. Florence Nightingale could see that Mary Seacole had done good work and wanted to give her some money."
Among the other myths he scotches are: she wasn't a malingerer or a hypochondriac, but suffered from the excruciatingly painful disease brucellosis, and she didn't take bromide to dampen down a ferocious sexual appetite but to ease the symptoms of spondylitis, which, says Bostridge, "is what kept her bedridden during the 1860s. Somebody once said that posterity has done Florence Nightingale a great disservice by saying she wasn't suffering from an organic disease. She was. I hope this book nails that myth once and for all."
At the height of Nightingale-fever, during the Crimean War, the family were receiving three poetic tributes a week (the phrase, "The Lady With the Lamp" comes from Longfellow's offering). Nightingale's reputation didn't suffer a dent until Lytton Strachey came along, with Eminent Victorians, though his essay on Nightingale, Bostridge points out, is not as debunking as people tend to think. "However, there's no doubt that his idea of this woman who sublimates her sexuality had an enormous impact," he contends. "James Pope-Hennessey said that Strachey made people snigger at Nightingale's name, which is exactly what happened. From that comes the idea of Florence Nightingale as a lesbian. There's no evidence for that!"
Bostridge has an evident sympathy with female subjects and a great sensitivity in writing about them. He has previously written a biography of Vera Brittain, and I remember him telling me once that in his teens he was "obsessed" with Charlotte Brontë. This sympathy dates back a long way, to a musical and literary upbringing he shared with his younger brother, the renowned tenor Ian Bostridge.
"In my childhood, I was always either singing or writing," he says. "I was one of those children who just wrote all the time, and when I was 11 I wrote my first biography, of Anne Boleyn, because there wasn't a modern biography of her – you had to go back to 1899." (I am charmed by his professional nous at so young an age.)
"I wrote it, and my father's secretary typed it up. It was called "The White Falcon". I still have it. I was writing about things I didn't understand – for example, Anne had a series of miscarriages, and it was difficult to understand what on earth that meant. I remember getting a book out of the adult library – you had to get special permission – called The Great Divorce. I remember the librarian saying to me, 'Oh, are you getting one?' I blushed to my roots, just taking the book out."
But why does he feel so attracted to writing about the lives of women in particular? Primarily, he says, it's the great stories they engender. "The two women I've written about had a real struggle against conventional society, and conventional ideas about what a woman is, and that is very dramatic and very interesting to me." He adds, more hesitantly: "I suppose I always think of myself as an outsider. It is to do with your upbringing, I think. My father was a very loving father and did every thing he possibly could for his children, but he did represent an extreme form of masculinity which I reacted against. I found it very frightening and I found those kind of masculine values very disturbing."
He explains that his father came from an archetypally hearty family; his father's maternal grandfather had been "quite a famous footballer before the First World War".
"To have both your children grow up, neither of them interested in sport, and both of them in effete occupations like writing and singing – it must have come as a considerable shock that he could have spawned two such children, but he was always very accommodating and always very proud of any achievements his children had. Especially my brother's, because my father died in 1998 and my brother's career had taken off by then. But it must have seemed – did seem – very peculiar to him."
As we approach the centenary of her death in 2010, there seems to be no sign yet of Florence Nightingale lying down and becoming a dusty old figure from history. "The whole question of the treatment of the army in Afghanistan, the sharp rise in maternal mortality and of course the problems with hospital infection – these are things that would have exercised her just as much today. Gracious, she would have been all guns blazing to ensure better treatment for soldiers who are fighting."
There will never be a definitive biography of such a figure, he suggests. "Somebody that enormous? In terms of studying her, we're really only at the beginning."
Florence Nightingale: The woman and her legend by Mark Bostridge (Viking £25)
"...Like an open sore, the question of Florence's jurisdiction in the Crimea, in the absence of any clarification of her orders, remained painfully unresolved. On 8 September 1855, Sebastopol finally fell after a siege of almost a year... The end of the war was confidently in sight. But Florence's bitterest struggles to assert her authority over the nursing in Crimean hospitals was only just beginning."