In a brilliant, definitive history of one of the most significant and controversial medical events of modern times, award-winning historian Michael Bliss brings to light a bizarre clash of scientific personalities. When F. G. Banting and J. J. R. Macleod won the 1923 Nobel Prize for discovering and isolating insulin, Banting immediately announced that he was dividing his share of the prize with his young associate, C. H. Best. Macleod divided his share with a fourth member of the team, J. B. Collip. For the next sixty years medical opinion was intensely divided over the allotment of credit for the discovery of insulin. In resolving this controversy, Bliss also offers a wealth of new detail on such subjects as the treatment of diabetes before insulin and the life-and-death struggle to manufacture insulin.