Defining the occupational chronology of Mont Castel

Aerial photograph of Mont Castel. Image: © Hervé Paitier / Inrap

Aerial photograph of Mont Castel. Image: © Hervé Paitier / Inrap

A vast coastal plateau covering around twenty hectares and dominating the village of Port-en-Besson (northwestern France), this archaeological site had never been subject to archaeological field investigation. It is thought that Mont Castel may be the port of the Baiocasses tribal group, in charge of overseeing the flow of merchandise between southern England and Normandy.

Mont Castel is part of a larger network of fortified sites that formed a protection system for this area, and unique in the Protohistory of western France.

Occupational chronology

While there is evidence that Mont Castel was occupied during Protohistory, the nature and chronology of this occupation remained to be defined. The topography and pieces of information available seem to indicate that it was a fortified site during the Final La Tene period (150-30 BC), of the oppidum type, situated in a remarkable and highly strategic location since the end of the Bronze Age (1350-800 BC).

Test-pits were undertaken in 2010 following the discovery that the site had been extensively looted. These tests confirmed the first hypotheses: the site was occupied during the Final Bronze Age, followed by the construction of fortifications at the very end of the Iron Age. These test-pits also yielded Roman armaments, including a sword scabbard, ballista or scorpio darts, and lead sling-shot bullets.

An obscure period

The period between the end of Gallic independence and the beginning of Romanisation – from 52 to 24 BC – is an obscure period for historians and archaeologists because the historical records provide only vague or indirect information on the political and social situation. The year 52 and the defeat of Alésia marked neither the end of the war against Rome, nor the immediate Romanisation of the Celtic society. The foundation of the material and spiritual culture of Gaul remained essentially indigenous until the Augustinian period. After the final battle of the Gallic Wars at Uxellodunum, the situation was not entirely under Roman control. Caesar had distributed all of his legions throughout Gaul and himself spent the winter of 51-50 at Nemetocena (Arras?). Gaul was exhausted, unstable and probably unsettled by internal conflicts, requiring the presence of an occupying army.

The discovery of late-républicain militaria on Mont Castel is new for western France, but it reflects archaeological discoveries on the grand oppida of northern and central-eastern Gaul. It supports the hypothesis that the first Roman military camps were installed on the oppida at the end of the conquest before being moved away from these urban centres during the Augustinian period.