Ancient Virus DNA Found Hidden in the Pages of a 1,000-Year-Old Gospel

Scientists have discovered traces of an ancient livestock virus preserved inside the parchment of medieval manuscripts, including the 1,000-year-old York Gospels.

The unexpected discovery has allowed researchers to reconstruct more than 3,500 years of the history of sheeppox virus, a highly contagious disease that has affected sheep for thousands of years.

DNA Hidden in Ancient Parchment

Medieval parchment was made from animal skins, meaning that the material used to create books could preserve biological information from the animals for centuries.

An international research team led by scientists at University College Dublin analyzed parchment from historic manuscripts and recovered genetic traces of sheeppox virus.

The York Gospels Reveal a Surprising Clue

Among the manuscripts examined were the York Gospels, an illuminated Gospel book produced around the late tenth or early eleventh century.

Researchers found sheeppox virus DNA on three pages associated with the manuscript. The discovery suggests that infected animals may have been among those whose skins were used to produce the parchment.

A Disease With Thousands of Years of History

The researchers also examined ancient sheep remains, including teeth dating back to the Bronze Age. By combining genetic evidence from animal remains and historical manuscripts, they were able to trace the evolution of the virus across thousands of years.

The oldest genetic evidence examined in the study dates to roughly 3,700 years ago, showing that sheeppox was already circulating among livestock long before modern veterinary records existed.

Manuscripts as Biological Time Capsules

The discovery demonstrates that historic books can contain information far beyond their written words and artwork.

Because parchment was produced from animal skin, ancient documents can preserve fragments of DNA that reveal diseases affecting livestock and the societies that depended on them.

Unexpected Evidence From Other Animals

Scientists also detected sheeppox virus DNA on some parchment made from calfskin and goatskin.

The researchers say this could reflect cross-species infection or contamination during the production of parchment. Further research will be needed to determine exactly how the viral DNA reached these materials.

What Ancient DNA Can Teach Scientists

Understanding how viruses changed over thousands of years can help researchers study their evolution and how diseases have affected livestock populations in the past.

The team believes that archives and libraries around the world could contain similar biological evidence hidden inside historic manuscripts, potentially opening a new way to investigate ancient animal diseases.

Sources

• University College Dublin — “Hidden DNA in medieval gospels reveals history of deadly livestock virus” — September 2, 2026.
• Science Advances — Research on the 3,500-year evolutionary history of sheeppox virus — 2026.
• Phys.org — “Ancient virus hunters: How we discovered sheeppox DNA hidden in medieval gospels” — September 2026.
• Ars Technica — “Medieval manuscripts are ‘biological time capsules’ for deadly sheeppox virus” — September 2026.