Knowing a fortress' layout can help you turn the battle to your advantage. Each fortress is essentially a residential area consisting of a large central command post surrounded by several barracks.
There are 5 types of barracks: defense barracks, archer barracks, support barracks, officer's barracks and a control room. The number of barracks varies depending on the size of the fortress. Each barracks has a commander who must be defeated in order for you to conquer that barracks. Note that the control center must have a Warsmith or a Maestro in order to handle the machinery.