Rather easy when compared to the final economic victory. Probably because historically I always took the battle campaigns and left the economic ones to cobwebs, so this mission wasn't that difficult.
I knew I would need money so pottery became a first focus, followed suit by the other needs. Splash in a fort, 2 every 3 years while building up weapons/armor, and you have yourself an easy victory. While not my swiftest success, it's still a victory.