Scientific testing has confirmed that graves uncovered beside St. John the Baptist Church in Altenberge, Germany, date to the Early Middle Ages. The finding gives the first direct scientific proof that the church site served as a Christian burial ground for more than 1,000 years, supporting a long-standing view held by historians.
Work photo showing the exposure of a securely dated 8th to 9th century burial. Credit: C. Golüke / Archäologie am Hellweg eG
The graves came to light during sewer replacement work around the Catholic parish church in autumn 2025. Archaeologists found 11 burials, though only part of the cemetery could be excavated because construction reached a limited area. Most of the graves followed a west to east layout, a common feature of early Christian burials.
The human bones were in good condition, making them suitable for radiocarbon dating. Researchers sent four samples to a laboratory in Vilnius, Lithuania. The dating method measures the natural decay of carbon-14 in bone and other organic material to estimate when a living organism died.
All four samples produced dates between the 8th and early 11th centuries. The matching results place the cemetery firmly in the Early Middle Ages. Archaeologists had expected an early burial ground based on the layout of the graves. The laboratory results now provide clear scientific proof.
13th-century rubble stone masonry north of the church. Credit: H. Neidhardt / Archäologie am Hellweg eG
The dating also supports earlier historical research about the church itself. Written records and past archaeological work pointed to an early medieval origin for the site. Until now, direct scientific evidence was missing. The new results fill that gap and confirm people used the area for Christian burial during the first centuries after the spread of Christianity across the region.
Researchers believe the parish church was founded as one of the original parish churches linked to Saint Liudger, the first Bishop of Münster, who died in CE 809. Historical research places the church on the grounds of a major episcopal estate. Original parish churches served as local centers for worship, burial, and daily life during the Early Middle Ages. Many villages later grew around these church sites.
View of the sewer trench during the excavation. Credit: H. Neidhardt / Archäologie am Hellweg eG
The excavation produced more than early medieval graves. Archaeologists also recorded the remains of a large stone cellar first uncovered in 2024. Pottery recovered from the structure dates the cellar to the 13th century, showing the area stayed in use for hundreds of years after the cemetery began.
The work formed part of a modern infrastructure project, though the archaeological results reached far beyond construction. The cemetery now stands as the oldest scientifically dated evidence for Christian burial at St. John the Baptist Church. Together with the medieval cellar, the finds trace a long history of life in Altenberge from the Early Middle Ages through the High Middle Ages.
More information: LWL Archaeology for Westphalia