Modern surgery developed in the second half of the 19th century, at the end of which neurosurgery was established as a profitable region of operative intervention. In the British Isles, the first exponent was Sir William Macewen (1848-1924) in Glasgow. But neuroscience had advanced in London due to the excellence of the neurologists in the several hospitals there. Foremost among English neurosurgeons was Victor Horsley whose career had a worldwide influence on the speciality. Initially, operations were carried out for cranial trauma, the removal of displaced bone or blood clot, and the drainage of abscesses arising from infection of the middle ears and air sinuses. The diagnosis of brain and spinal tumours by neurologists encouraged removal by surgeons, of which Horsley was among the earliest. Horsley performed many operations on animals, experiments opposed by the anti-vivisectionists whose campaigns Horsley countered. Horsley had many other interests, some of which displeased the establishment, and in World War I his experience in neurosurgery was not used. He served as a general surgeon, visiting Egypt, India and Mesopotamia where, in Amara, he died from hyperpyrexia complicating bacillary dysentery.