The campaign spans 7 distinct worlds. You begin in Roma, the cradle of civilization.
You will march through Galia, Hispania, Britannia, Germania, Dalmatia, and finally Thracia.
Each world introduces new enemy types. In Germania, the forests hide ambushers. In Britannia, the fog protects their archers.
You cannot use the same strategy everywhere. Adapt to the terrain and the enemy faction, or your conquest will end in the mud.