You are in charge of defending The Reveille from Duc Beauregard and Duc de Puce. It's not just spears and maces this time. The Snake learned about swords and pikes, however will not give this information to the Rat. Iron is unavailable so you're going to have to buy the metal weapons at the market.
Not into invasion maps?
There's an economics map as well. Repair the port that was damaged 70 years ago (invasion map). You're in debt though, you're required to regain the gold to complete the mission.