This book offers an introduction to the history of university-trained physicians from the middle ages to the eighteenth-century Enlightenment. These were the elite, in reputation and rewards, and they were successful. Yet we can form little idea of their clinical effectiveness, and to modern eyes their theory and practice often seems bizarre. But the historical evidence is that they were judged on other criteria, and the argument of this book is that these physicians helped to construct the expectations of society - and met them accordingly. The main focus is on the European Latin tradition of medicine, reconstructed from ancient sources and relying heavily on natural philosophy for its explanatory power. This philosophy collapsed in the 'scientific revolution', and left the learned and rational doctor in crisis. The book concludes with an examination of how this crisis was met - or avoided - in different parts of Europe during the Enlightenment.