Florence Nightingale was a celebrated English nurse, writer and statistician. A Christian universalist, Nightingale believed that God had called her to be a nurse. She came to prominence for her pioneering work in nursing during the Crimean War, where she tended to wounded soldiers. She was dubbed "The Lady with the Lamp" after her habit of making rounds at night. Nightingale laid the foundation of professional nursing with the establishment, in 1860, of her nursing school at St Thomas' Hospital in London, the first secular nursing school in the world. The Nightingale Pledge taken by new nurses was named in her honour, and the annual International Nurses Day is celebrated around the world on her birthday.