Celts were certainly urban, with well established settlements, government, trade and skilled in metalwork and even had roads of a sort. They built in wattle and doab and wood, not brick and stone, but they had civilisation, none the less. But since it wasn't the Roman's idea of civilisation, they put them down. The Celts had pillaged Rome itself in the 4th Century (just before the start date of this game) and the Romans never really got over it. The Celts were forever after the boogie man of Roman civilization - they were Rome's paranoid fear, the stereotypical traditional enemy, and this was played upon in Roman writings. Romans needed to feel superior to the Celts, to allay/disguise their fears, and to justify their invasions, so the Celts were usually portrayed as barbaric and a threat. Accuracy be damned. Roman writings had too much credibility for far too long and so the image of the Celts being savages have been passed down and ingrained into the modern mindset. But they weren't really. They had civilisation - it was just different to that of the Romans.
