DNA from the bones of medieval leprosy victims is helping scientists improve their understanding of the disease.
The samples, extracted from skeletons buried at the St Mary Magdalen Hill leprosy hospital in Winchester, Hampshire, were used to construct the entire genome, or genetic code, of the ancient leprosy bacterium.
A waxy coat surrounding the bug is believed to have protected it from degradation over the centuries.
The disfiguring disease was once endemic in Europe but largely disappeared during the Middle Ages.
Lead scientist Professor Graham Stewart, from the University of Surrey, said: “Understanding diseases from the past will help us predict emerging infectious diseases and potentially suggest how we may be better able to control existing diseases.
“We hope to analyse even older DNA, tracing leprosy and also tuberculosis back to their origins in human history.”