Sir Geoffrey Keynes (1887 - 1982), was a pioneer in the surgery of breast cancer and thymic deseases, n.b. in patients suffering from myastenia gravis. He strongly disapproved of the longstanding dogma of so called radical mastectomy in breast cancer, and advocated a more limited surgical approach, followed by radiation therapy. This was done more than fifty years before breastconserving surgery has become the therapy of choice and against considerable opposition from the surgical establishment of his days. He also became a pioneer in the surgical treatment of myastenia gravis by thymectomy, at a time when there was no real understanding of the pathophysiology of the disease and when considerable controversy existed as to the importance or non importance of concomitant tumour formation in the thymus. Besides being a busy surgeon Sir Geoffrey was a medical historian, writing the biography of among others William Harvey, a bibliographer with a special interest in the poet and artist William Blake and a bibliophil with a large book collection of great value to medical history.