Today, frenzy is the stuff of newspaper headlines. Five hundred years ago, it described a disease which could kill its sufferers within days. This book offers the first full-length study of frenzy, providing a fresh perspective on early modern understandings of mental illness, mind-body relations, and personhood. Frenzy was frightening not just because it killed its sufferers, but because it changed them beyond recognition. It gave the impression that what was then the most precious part of the person – the soul – was as easy to damage as the body. Frenzy in Early Modern England deepens and complicates our sense of what madness meant in this period, both to those who assigned the label, and to those who lived with it. This is an important intervention in the often-fragmented historiography of early modern madness, combining intellectual, social, and cultural history with the history of medicine.