A medical-historical essay recounts a series of late medieval English epidemics known as the sweating sickness, drawing on contemporary chronicles and later commentators to trace outbreaks from the late fifteenth century through the mid sixteenth. It describes characteristic clinical features—very rapid onset, a short often fatal course, profuse unpleasant sweating, tendency to relapse, and a striking attack rate among vigorous adults across social ranks—and evaluates theories about origin and transmission, including possible links to military movements versus native emergence. The account synthesizes documentary evidence to map the disease’s spread and to prepare for a subsequent analysis of its nature.