Until quite recently, historians have been obliged to rely upon documentary sources for most of their information about the health of medieval men, women and children. The most common ailments, or at least those which appeared treatable, find mention in remedy books and herbals. The lives of saints and accounts of their healing miracles likewise provide a catalogue of disease and debility, in this instance carefully chosen to reflect the superiority of spiritual over earthly medicine. Important evidence about the incidence of epidemics and famines was recorded by chroniclers, although they, in common with other medieval writers, employed a terminology that makes retrospective diagnosis difficult, if not impossible. Since the 1960s, however, advances in the study of palaeopathology (the analysis of excavated skeletal remains) have enabled us to gain a far more detailed and comprehensive picture of levels of mortality and morbidity in the years between 900 and 1200.

It is important to stress that many diseases, such as diphtheria and pneumonia, affect only the perishable soft tissue of the body, while others may prove fatal at a comparatively early stage and thus escape detection. Nor can we generalize too widely on the basis of limited data relating to particular groups of people with specific problems. Even so, skeletal evidence has proved invaluable in illuminating the lives and deaths of low-status individuals whose voices otherwise remain mute, or who are barely mentioned in the historical record.