In eighteenth-century Britain, gaols were places of temporary confinement, where inmates stayed while awaiting punishment. With the rise of the 'penitentiary' from the early nineteenth century, custodial institutions housed prisoners for much longer periods of time. Prisoners were supposed to be reformed as well as punished during their incarceration. From at least the time of John Howard (1726-1790), the health of prisoners has been part of the concern of philanthropists and others concerned with the wider functions of prisons. The Victorians established a Prison Medical Service, and members of the medical profession have long been involved in caring for the mental and physical needs of prisoners. For two centuries, prison overcrowding has been identified as a major cause of mortality and morbidity in prisons. Historical debates thus often have a modern ring to them, which make the essays in this volume particularly timely.