A thousand-year-old gospel book has become an unlikely time capsule for a devastating livestock disease. Scientists found fragments of sheeppox virus DNA in the parchment of the York Gospels and other historic manuscripts, helping reconstruct the pathogen’s history across more than 3,700 years.
The discovery came from an international research project led by Dr. Kevin Daly of University College Dublin. Rather than treating parchment as merely a writing surface, the team analyzed the animal skins used to make it, recovering viral material preserved in manuscripts produced across medieval Europe. The study, published in Science Advances, identified 21 previously unknown ancient sheeppox genomes spanning the Eurasian Bronze Age through the early modern period.
The York Gospels, an exceptionally important illuminated manuscript from the early Anglo-Saxon period, contained viral DNA on three pages, including a later legal document attached to the book. Researchers also detected sheeppox traces in the Corpus Glossary, an early Latin-to-Old English dictionary, along with other religious and legal manuscripts. In total, the broader investigation identified the virus in 39 archaeological and historical specimens, including sheep teeth and parchment or paper associated with medieval documents.
The oldest evidence came from sheep teeth found on the Eurasian steppe and dated to roughly 1700 BCE. Those samples show that sheeppox was already circulating among domesticated herds at least 3,700 years ago, while the manuscript genomes reveal how closely related forms persisted much later. The researchers estimate that major capripoxvirus lineages diverged between approximately 11,500 and 3,700 years ago, during periods when sheep husbandry and animal movement were expanding across Eurasia.
Sheeppox is not simply an ancient curiosity. The contagious disease can cause fever, widespread skin lesions, internal damage and death in sheep and goats, posing a serious threat to herds and food security. The World Organisation for Animal Health lists sheep pox and goat pox among diseases associated with severe illness and mortality, particularly in vulnerable animals. The new genetic record gives researchers a longer view of how the virus adapted to livestock and moved alongside human communities.
The findings also demonstrate why conservators and scientists are increasingly treating historic objects as biological archives. Sampling priceless manuscripts required extremely small collections of material, including careful removal of surface particles from parchment. That approach could allow other books, legal records and religious artifacts to reveal evidence of pathogens without turning cultural treasures into laboratory specimens. For the York Gospels, the result is a startling new layer of history: alongside ink, illumination and centuries of human use, its pages preserve clues to a disease that shaped animal life long before the book was made.
