She hated the limelight and shunned all publicity, so photographs of the nurse Florence Nightingale, the fabled Lady of the Lamp, are extremely rare.
But today, 150 years to the day since her return from the Crimean War, a new image, recently discovered in a collection of 19th-century photographs, will go on public display.
The picture shows Florence Nightingale sitting reading in the grounds of her family home at Embley Park, Hampshire, a couple of years after the end of the war which made her name.
It was taken by William Slater, a Hampshire chemist, councillor and amateur photographer who lived near her family. He met Nightingale when she ordered a medical box from him to take to Crimea. With other photographs of the period, including those of the nurse's sister Parthenope, Prime Minister Lord Palmerston, a neighbour, and other dignitaries, the collection passed through generations of the Slater family to William Slater who died in December.
Alerted by a local newspaper story on the albums in June, the Florence Nightingale Museum in London contacted Mr Slater's beneficiaries, who have donated one of three surviving albums to the museum's collection so it can be publicly viewed.
The photograph of Florence Nightingale, previously unknown, is one of only eight in existence.
Alex Attewell, director of the museum, said: "This is a very significant find. Given her fame and that she lived into the 20th century  it's pretty unusual there are so few photographs of her. This one will help us to illustrate a period of her life often overlooked in favour of the 'Lady of the Lamp' legend."
On her return from war, Florence Nightingale dedicated herself for 30 years to behind-the-scenes public service, helping to transform the profession of nursing, reforming army health care and improving hygiene standards in hospitals. Mark Bostridge, the author of a forthcoming biography of Nightingale, said the picture was an exciting discovery: "She was extremely reluctant to be photographed, being determined 'in no way to forward the making of a show of herself,' partly for religious reasons and also because she regarded any personal publicity as detrimental to the causes of public health for which she worked so tirelessly after her return from the Crimean War.
"The photograph conveys the lean intensity of a woman who, despite her own ill-health, was masterminding the Royal Commission into the Health of the British Army."
Returning to London on 7 August 1856, she first visited the nuns of the Convent of our Lady of Mercy at Bermondsey before taking the train to Derbyshire to her home at Lea Hurst, arriving without notice.
Although she was a national heroine, she became obsessed by a sense of failure and was haunted by the facts of preventable disease. At the period of this photograph, she was generally regarded as reclusive.
The Florence Nightingale Museum, which is based at St Thomas' Hospital in London, will display the "new" photograph until 7 November.Reuse content