On the campaign map, settlements have a zone of control which prevents enemy armies from going too close without attacking.

Most settlements will have garrison armies which are provided by the main settlement building, and protect the settlement from attacks. The controlling faction may also position an army directly a settlement to 'garrison' it. If a settlement has walls, then armies have the option to lay siege to a settlement before attacking.If there is a garrison and/or defending army, then attacking the settlement will initiate a battle or autoresolve.If there is no garrison and no defending army, then a settlement can be taken without a battle.Additionally, armies which are close by can reinforce a settlement garrison in battle. When they do choose to attack, it will be a siege battle.

Settlements become ruined when they are razed by a hostile army.Some settlements on the campaign map begin as ruins.Ruined settlements are not controlled by any faction and do not provide income or other bonuses.Winning the battle for a settlement brings up the settlement options such as occupy, sack, raze etc.

Mortal empires map ruins