Born in Gravenhurst, Bethune studied medicine in Toronto. He made significant contributions to thoracic surgery in Montréal hospitals, and became a strong advocate of socialized medicine. In 1936-37, during the Spanish Civl War, he led a Canadian medical team which, while serving with the Republican forces, pioneered the use of mobile blood transfusion services. He subsequently worked as a battlefield surgeon and medical adviser with the forces of Mao Tse-tung. After his death at the war front, on November 12, 1939, he became a national hero in China.