Loyalty is a point scale an attacker needs to reduce to 0 (usually from 100) in order to take over a village.
Loyalty can only be viewed by the owner of a village and an attacker of a village (if it is attacked with a nobleman unit). It only appears in an owners "village overview" only if its less than 100.
It can only be reduced by an attack with a nobleman. Each attack that is sent with a nobleman to plunder a village's resources will reduce said village's loyalty by 20-35 points. If a village has 0 loyalty, it will become incorporated into the last attacking players set of villages.
Loyalty will regenerate at rate of 1 point per hour until it reaches 100 again.
As with any other unit, a nobleman can die in an attack and quite easily (based on its defense, see nobleman). It is advised that an attacker sends an attack without a nobleman first to destroy all the enemy soldiers and then attack with a small army including said nobleman immediately after...