Harvey Cushing (1869-1939) is considered to be the father of modern neurological surgery. In the early part of the 20th century, he developed basic techniques and instruments for operating on the brain and, as a result, founded the discipline as a distinct surgical speciality. Before Cushing began his career, brain tumours were considered to be inoperable, and the mortality rate for any surgical procedure which involved opening the skull was around 90%. Early in his career, Cushing dramatically reduced the mortality rate for neurosurgery to less than 10%, and by the time of his retirement in 1937, he had successfully removed more than 2,000 tumours.