Stereotactic radiosurgery is a modern discipline that emerged after World War II. It represents a synthesis of an approach to patient care that was not immediately embraced by either neurosurgeons or radiation oncologists, but which has been shown, time and again, to be advantageous for the treatment of intracranial pathology. Indeed, stereotactic radiosurgical techniques are now being rapidly adapted and adopted for the treatment of extracranial malignant and benign disease. Any examination of the individuals, devices, and technological advances that permitted stereotactic radiosurgery to become a preferred approach for patient care cannot be absolutely comprehensive but can provide insights into the evolution of the specialty and potential future prospects for further improvements in patient care. As Shakespeare wrote in The Tempest, "What's past is prologue."