Leprosy was an iconic disease in medieval Europe. From the 11th century, several leprosy hospitals were founded as a mitigative response to the risk of infection. Medieval treatises and chronicles suggest that leprosy was treated with medicinal plants and other ingredients of mineral and animal origin. However, very little is known about the methods used to diagnose and treat this disease within leprosaria, and medical treatments of leprosy have very rarely put in their physical context so far. Through the analysis of the dental calculus, the MEDICAL project aims to explore the medical care offered to people who experienced leprosy and lived in leprosaria in Northern Europe during the medieval period (1100-1550AD). To date, these medical treatments have never been analysed from an archaeological perspective and the study of skeletal remains recovered from selected historic leprosy cemeteries offers an unparalleled opportunity to investigate medical treatments further. The MEDICAL project will focus on two north European case studies: the cemeteries of St. Leonard at Peterborough (England) and Saint-Thomas d’Aizier (France). The research will be developed at the Department of Oral and Maxillo Facial Sciences at the Sapienza University in Rome (host institution) and at the Department of Archaeology of Durham University (secondment). Under the supervision of Professor Emanuela Cristiani (Rome) and Professor Charlotte Roberts (Durham), the applicant Dr Elena Fiorin will analyse human dental calculus employing optical microscopy, Scanning Electron Microscopy with X-ray microanalysis using Energy and Wavelength Dispersive X-ray Spectroscopy, and Inductively Coupled Plasma Mass Spectrometry. This project ultimately seeks to shed new light on the history of medieval medicine developing a novel and fresh archaeological methodology for the study of infectious diseases in the ‘golden age of bacteria’.