Enlarge / View of the Las Gobas cave site. (credit: Miguel Sotomayor via Getty)

In a new study, we have sequenced DNA from a Christian community in medieval Spain that lived in artificial caves carved into a rocky outcrop.

This is one of several medieval cave communities known to have lived on the Iberian Peninsula—which includes both Portugal and Spain. Why these groups favored caves over more conventional village dwellings is a subject of longstanding debate for archaeologists. While it may be tempting to speculate about hermits or religious groups, there’s scant evidence to support such theories.

Our study, published in Science Advances, explores the possibilities, adding genetic analysis to what we know about the physical remains of people from the site’s cemetery. DNA was able to shed light on the ancestry of this community, their relationships to each other and the diseases that afflicted them.