Pyro
Chieftain
please name a few barbarian or celtic city that was more than a village at that time and that's still a known city nowadays.
Why not Geneva? That was founded by Celts... or Basle. I'd love a swiss city included, even when it's just barb!

But Geneva's probably too close to Mediolanum... hmmm...
Alt.: Parisii: Gaulish Tribe. Centred on their capital city of Lutetia, with the city's main fortress built on an island in the middle of the Sequana River. The Parisii are a strategically important tribe, as they control the gateway between northern and southern Gaul. Lutetia reportedly has never been taken by assault in the endemic inter-tribal warfare of Gaul and for that reason the Parisii are not to be discounted in the power struggle of the tribes. They are ruled by their chief Theuderix.