Sir Geoffrey Langdon Keynes (/ ˈ k eɪ n z / KAYNZ; 25 March 1887, Cambridge – 5 July 1982, Cambridge) was a British surgeon and author. He began his career as a physician in World War I, before becoming a doctor at St Bartholomew's Hospital in London, where he made notable innovations in the fields of blood transfusion and breast cancer surgery.Keynes was also a …