Ever since the 19th century, French and British scholars have been interested in Caesar’s campaigning during the Gallic war. In reconstructing the famous sieges by means of which he conquered Gaul, we can see, however, that most authors look at the war from the Roman side. The way the Gauls defended themselves against the Romans is rarely examined. The methods of defence they deployed in the course of the sieges can be partially inferred from Caesar’s text, which gives us a few clues here and there about the way in which the Gauls used their fortifications in the heat of action. Archaeological research on Iron Age ramparts means that we now have a far better understanding of both the architecture and the functioning of the defensive works constructed by the Gauls. Even if some ramparts may have been built in peacetime, as with some muri gallici, the enormous dump ramparts of central France are truly technological undertakings clearly conceived for war. This applies particularly to fortifications in the territory of the Bituriges, whose main centre, Bourges – ancient Avaricum, was besieged by Caesar in 52 BC. One of the largest civitates in Gaul in the 1st century BC, their territory boasts a series of late Iron Age fortifications which have been studied and excavated for more than 40 years (Bourges, Levroux, Châteaumeillant, Argentomagus and Hérisson).This talk presents the results of recent excavations on the ramparts of central France and will show that the Gauls mastered a specific technology combining architectural design and military ingenuity. By bringing together the archaeological evidence and the textual sources, we can examine the fortifications in the light of the defensive tactics employed by the Gauls. In particular, we will see that the dump rampart, the ultimate Celtic model, is not simply a mound of earth. On the contrary, it embodies the implementation of a sophisticated technology at the heart of which the murus gallicus was an important asset for thwarting the Romans’ saps and mines.< Réduire