Which famous nurse was called the Lady with the Lamp?

Florence Nightingale, from the image of her walking the wards at Scutari at night during the Crimean War. The lamp is the part everyone remembers and the least important thing she did.

Her real weapon was statistics. She found that far more soldiers were dying of typhus, cholera and dysentery than of wounds, and she proved it with data, inventing a form of diagram - the polar area chart, still called a Nightingale rose - specifically because she needed to convince politicians and generals who would not read a table. She was elected the first female member of the Royal Statistical Society in 1858.

The sanitary reforms that followed - drains, ventilation, clean water, laundry - cut death rates enormously, and she spent the rest of her life applying the same method to hospital design, army administration and public health in India. She did most of that from bed: she returned from Crimea with a chronic illness, probably brucellosis contracted there, and was largely bedridden for decades while writing hundreds of reports that reshaped how hospitals were built.