This book is concerned with the most devastating fungal diseases in history. These are the plagues of trees and crop plants caused by invisible spores that have reshaped entire landscapes and decimated human populations. Everyone is aware of the Irish potato famine, but while many other fungal diseases are less familiar, they have had similarly disastrous consequences. The book focuses on the fascinating biology of the well- and lesser-known diseases, and tells the stories of the scientists involved in their study and of the people directly impacted by the loss of forest trees like the chestnut, and cash crops such as coffee and cacao. While a book about fungal epidemics is not tailor-made for an intoxicating and uplifting read, the story of the mycologists and plant pathologists engaged in combating these diseases is one of human optimism (often encouraged by desperate eccentricity). In a surprisingly brief time, human knowledge of the fungi that infect plants has evolved from Biblical superstition to the recognition of the true nature of plant disease, and more recently, to a sense of awe for the sophistication of these microbes. The crucial issue of human culpability in these fungal epidemics is addressed in the book’s closing chapter.