In De Bello Gallico, Caesar talks about various towns in the lands of the Biturige, usually using the word "oppidum".

Today, strong differences of opinion exist amongst researchers of how we should arrive at an archaeological definition of this term.

To simplify matters, we'll define it as a permanent, fortified habitat playing an important role in the territory of a Gaulish tribe. A territory would consist of several or many oppida, all of which would assume some political, social and economic function.