An ornate Bronze Age stone slab which was excavated in France in 1900 and forgotten about for over a century has been revealed to be the oldest known map in Europe.
Researchers from the French National Institute for Preventive Archaeological Research (Inrap), ²¤ÂÜÊÓƵ, the CNRS and the Université de Bretagne Occidentale (UBO – University of Western Brittany) examined the carved slab from Saint-Bélec (Leuhan, Finistère Department), which dates from the early Bronze Age (2150-1600 BCE).
Their study, published in French journal Bulletin de la Société préhistorique française, has identified it as the oldest cartographical representation of a known territory in Europe, a probable marker of the political power of a principality of the early Bronze Age.
The broken slab was re-used in the burial of the Saint-Bélec towards the end of the early Bronze Age (c. 1900-1640 BCE). At the time, the slab formed one of the walls of a stone-cist, a small stone coffin-like box used to hold the bodies of the dead. Its engraved face was turned towards the inside of the tomb, but its ends were hidden.
The slab was moved to a private museum in 1900 before the collection was acquired by the Musée des Antiquités nationales (MAN – Museum of National Antiquities) in 1924. Until the 1990s, the Saint-Bélec Slab was stored in a niche in the castle moat. Finally, in 2014, it was found in a cellar of the castle.
The research team, including BU Post-Doctoral Researcher Dr Clément Nicolas, started carrying out high-resolution 3D surveys and photogrammetry of the slab in 2017, recording the surface of the slab and its engravings. Â
They found that the slab bears many of the elements expected in a prehistoric map – including repeated motifs joined by lines to give the layout of a map.
An examination of the engraved surface shows that the slab’s topography was purposely 3D-shaped to represent the valley of the River Odet, whilst several lines appear to depict the river network.
The team also analysed the similarities between the engravings on the slab and elements of the landscape.
This work showed that the territory represented on the slab appears to relate to an area of about 30 km by 21 km, along the course of the River Odet. The central motif, interpreted as a symbol of an enclosure, suggests that the centre of a territory might have existed within three river springs (the Odet, the Isole, and the Stêr Laër).
The Saint-Bélec Slab is contemporaneous with the famous  found in Germany, the oldest known concrete depiction of the cosmos, and highlights the cartographic knowledge of prehistoric societies.
The Saint-Bélec Slab depicts the territory of a strongly hierarchical political entity that tightly controlled a territory in the early Bronze Age, and breaking it may have indicated condemnation and deconsecration.
Its burial and an iconoclastic act may have marked the end or the rejection of the elites who exercised their power over the society for several centuries during the early Bronze Age.