The Massachusetts General Hospital (MGH) has a history of excellence and is internationally recognized as a world class medical center, providing quality medical care, advancing medicine through clinical and laboratory research and facilitating the education of exceptional health care professionals. The Massachusetts General Hospital Radiation Oncology Department, staff, residents and fellows, past and present, concur that MGH stands for Man’s Greatest Hospital. This decidedly immodest assessment is widely viewed amongst this group as being manifestly true, and that perception is clearly reflected in a marvelous esprit de corp. Such an unequivocally positive attitude is solidly based on the judgment that the best possible care is provided to each MGH patient, i.e. the patient is, in fact, Number One. There is a deep sense of pride in the contributions made by this department to the scientific advancement of oncology, and to progressively and substantially increasing the proportion of patients who are free of tumor and of treatment related morbidity. Evolution of Radiation of Oncology at Massachusetts General Hospital is the work of the former Chair of the Department, Herman D. Suit. From 1970 – 2000, his guidance and management of this Department brought it to recognition as a world class center. Dr. Suit was key in the development and building of the Department that now includes The Northeast Proton Therapy Center at the MGH. His passion for the science of radiation therapy and its evolving growth through the years is evident in this book. He has assembled a fascinating chronicle, beginning with the creation of MGH in 1811 followed by personal experiences that culminated with his leadership of the Radiation Oncology Department.