Archaeologists excavating a hilltop site in eastern France have uncovered evidence of a large palatial complex dating to the early Middle Ages. The discoveries at Montagne de Saint-Laurent, near Dijon, include substantial stone buildings, a church and Roman-style underfloor heating, offering new insights into the lives of Burgundy’s elites between the fifth and eighth centuries.
The findings were announced by France’s National Institute for Preventive Archaeological Research (Inrap), following the latest excavations at the site in Mesmont, approximately 20 kilometres west of Dijon. Archaeological investigations have been taking place there since 2019, with a new three-year research programme beginning in 2026.
The site occupies a prominent hill overlooking the Ouche valley and has a long history of human activity stretching back to the Neolithic period. However, the current research focuses on the fifth to eighth centuries, when the hilltop became a densely occupied settlement with substantial masonry buildings.
The most significant discoveries have been made on the western side of the hill’s central summit, where archaeologists have identified a complex of large stone buildings arranged around a church.
The church, first discovered in the 1970s and excavated between 2019 and 2024, measures 27.5 metres in length and 12.4 metres in width. Its religious function had previously been uncertain because no associated burials had been found. However, the discovery of a chancel screen and the foundations of what may have been a liturgical bench has allowed archaeologists to identify it as a substantial place of worship. An adjoining room to the south may have served as a presbytery annex.
Immediately west of the church, excavations in 2026 uncovered another masonry building measuring 15 by 12 metres. The thickness of its walls and the quality of the mortar suggest that it may have supported an upper floor. Further investigations south of the church revealed another large structure extending more than 20 metres in length, although its full dimensions remain unknown.
Together, these buildings form an extensive architectural complex covering several hundred square metres, with structures arranged in a regular, orthogonal layout.
Among the most interesting discoveries are remains of a Roman-style heating system. Archaeologists recovered numerous pilae, the small supports used to raise floors, along with fragments of pipes and suspensura, or suspended concrete flooring. These indicate the presence of a hypocaust system, which circulated heated air beneath floors.
Such installations required specialised craftsmen and considerable resources. Their presence suggests that the buildings were occupied by wealthy individuals capable of financing elaborate construction projects and maintaining comforts associated with Roman elite residences.
Pottery discoveries, including examples of terra sigillata produced in the Argonne region, together with radiocarbon dating, indicate that the complex was constructed during the fifth century and remained occupied until the beginning of the eighth century, apparently without major alterations.
Other discoveries reinforce the impression that Montagne de Saint-Laurent was home to a privileged community. More than 500 glass fragments have been recovered since excavations began in 2019. These include remains of lamps and tableware, objects associated with wealthy households during the early Middle Ages. Approximately 50 fragments consist of flat glass, probably used in the windows of the church.
The archaeological evidence also corresponds with medieval written sources that identify Mesmont as an important regional centre.
During the early Middle Ages, the settlement served as the chief town of the pagus magnimontensis, a territorial district within the episcopal territory of Langres. These pagi were administrative and geographical divisions that, in some respects, anticipated the counties of the later Middle Ages.
Historical sources describe Mesmont using the terms castrum and oppidum, suggesting a fortified or elevated settlement that also possessed certain urban characteristics.
The combination of these written references and the newly uncovered buildings suggests that Mesmont played a significant role in the organisation of political and religious authority in early medieval Burgundy.
The site is also associated with Saint Antide, whose name survives in several nearby churches and settlements. His relics were probably preserved at Mesmont until the ninth century, when they were transferred to Brescia in northern Italy. Researchers believe this transfer may reflect the settlement’s decline, as regional importance gradually shifted towards nearby Sombernon.
The palatial complex forms part of a much larger early medieval settlement that archaeologists are gradually reconstructing through excavations, geophysical surveys and LiDAR mapping.
Elsewhere on the plateau, researchers have identified several substantial masonry buildings. One structure, dating to the sixth or seventh century, covers nearly 240 square metres. Its construction materials and complex internal arrangement suggest that its occupants also enjoyed considerable social standing.
Another area of interest is the present-day cemetery of Mesmont, which occupies the location of a medieval church known from written sources. The cemetery enclosure has a basilica-like plan, with an apse at its eastern end, while earlier discoveries of graves and a sarcophagus lid provide further evidence of medieval religious activity.
Despite these discoveries, important questions remain about the settlement’s inhabitants and the precise functions of its buildings. The site has also suffered repeated looting by metal detectorists, resulting in the loss of metal artefacts that might have provided valuable information about its occupants.
The ongoing excavations offer an unusual opportunity to investigate an early medieval hilltop settlement on a large scale. Such sites are rarely examined in their entirety, often because they are difficult to access or lie beneath later settlements.
For archaeologists, Montagne de Saint-Laurent offers an opportunity to understand how political power, religious institutions and elite lifestyles developed in Burgundy during the transition from Roman Antiquity to the Middle Ages.
The research programme will continue over the coming years, with further excavations expected to clarify the organisation and functions of this important early medieval settlement.
Archaeologists excavating a hilltop site in eastern France have uncovered evidence of a large palatial complex dating to the early Middle Ages. The discoveries at Montagne de Saint-Laurent, near Dijon, include substantial stone buildings, a church and Roman-style underfloor heating, offering new insights into the lives of Burgundy’s elites between the fifth and eighth centuries.
The findings were announced by France’s National Institute for Preventive Archaeological Research (Inrap), following the latest excavations at the site in Mesmont, approximately 20 kilometres west of Dijon. Archaeological investigations have been taking place there since 2019, with a new three-year research programme beginning in 2026.
The site occupies a prominent hill overlooking the Ouche valley and has a long history of human activity stretching back to the Neolithic period. However, the current research focuses on the fifth to eighth centuries, when the hilltop became a densely occupied settlement with substantial masonry buildings.
A Palatial Complex with Roman-Style Heating
The most significant discoveries have been made on the western side of the hill’s central summit, where archaeologists have identified a complex of large stone buildings arranged around a church.
The church, first discovered in the 1970s and excavated between 2019 and 2024, measures 27.5 metres in length and 12.4 metres in width. Its religious function had previously been uncertain because no associated burials had been found. However, the discovery of a chancel screen and the foundations of what may have been a liturgical bench has allowed archaeologists to identify it as a substantial place of worship. An adjoining room to the south may have served as a presbytery annex.
Immediately west of the church, excavations in 2026 uncovered another masonry building measuring 15 by 12 metres. The thickness of its walls and the quality of the mortar suggest that it may have supported an upper floor. Further investigations south of the church revealed another large structure extending more than 20 metres in length, although its full dimensions remain unknown.
Together, these buildings form an extensive architectural complex covering several hundred square metres, with structures arranged in a regular, orthogonal layout.
Among the most interesting discoveries are remains of a Roman-style heating system. Archaeologists recovered numerous pilae, the small supports used to raise floors, along with fragments of pipes and suspensura, or suspended concrete flooring. These indicate the presence of a hypocaust system, which circulated heated air beneath floors.
Such installations required specialised craftsmen and considerable resources. Their presence suggests that the buildings were occupied by wealthy individuals capable of financing elaborate construction projects and maintaining comforts associated with Roman elite residences.
Pottery discoveries, including examples of terra sigillata produced in the Argonne region, together with radiocarbon dating, indicate that the complex was constructed during the fifth century and remained occupied until the beginning of the eighth century, apparently without major alterations.
An Important Centre in Early Medieval Burgundy
Other discoveries reinforce the impression that Montagne de Saint-Laurent was home to a privileged community. More than 500 glass fragments have been recovered since excavations began in 2019. These include remains of lamps and tableware, objects associated with wealthy households during the early Middle Ages. Approximately 50 fragments consist of flat glass, probably used in the windows of the church.
The archaeological evidence also corresponds with medieval written sources that identify Mesmont as an important regional centre.
During the early Middle Ages, the settlement served as the chief town of the pagus magnimontensis, a territorial district within the episcopal territory of Langres. These pagi were administrative and geographical divisions that, in some respects, anticipated the counties of the later Middle Ages.
Historical sources describe Mesmont using the terms castrum and oppidum, suggesting a fortified or elevated settlement that also possessed certain urban characteristics.
The combination of these written references and the newly uncovered buildings suggests that Mesmont played a significant role in the organisation of political and religious authority in early medieval Burgundy.
The site is also associated with Saint Antide, whose name survives in several nearby churches and settlements. His relics were probably preserved at Mesmont until the ninth century, when they were transferred to Brescia in northern Italy. Researchers believe this transfer may reflect the settlement’s decline, as regional importance gradually shifted towards nearby Sombernon.
Uncovering a Forgotten Hilltop Settlement
The palatial complex forms part of a much larger early medieval settlement that archaeologists are gradually reconstructing through excavations, geophysical surveys and LiDAR mapping.
Elsewhere on the plateau, researchers have identified several substantial masonry buildings. One structure, dating to the sixth or seventh century, covers nearly 240 square metres. Its construction materials and complex internal arrangement suggest that its occupants also enjoyed considerable social standing.
Another area of interest is the present-day cemetery of Mesmont, which occupies the location of a medieval church known from written sources. The cemetery enclosure has a basilica-like plan, with an apse at its eastern end, while earlier discoveries of graves and a sarcophagus lid provide further evidence of medieval religious activity.
Despite these discoveries, important questions remain about the settlement’s inhabitants and the precise functions of its buildings. The site has also suffered repeated looting by metal detectorists, resulting in the loss of metal artefacts that might have provided valuable information about its occupants.
The ongoing excavations offer an unusual opportunity to investigate an early medieval hilltop settlement on a large scale. Such sites are rarely examined in their entirety, often because they are difficult to access or lie beneath later settlements.
For archaeologists, Montagne de Saint-Laurent offers an opportunity to understand how political power, religious institutions and elite lifestyles developed in Burgundy during the transition from Roman Antiquity to the Middle Ages.
The research programme will continue over the coming years, with further excavations expected to clarify the organisation and functions of this important early medieval settlement.
Top Image: View of the apse and choir of the summit church during excavation in 2022. © A. Guicheteau, Inrap
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