This i would think would be just a minor tweak to the mod. If a civilization (im basing this on Rome) is conquered defeated or in most cases collapses and returns to the game in the later future, change the name of the civ. Like if some how spain or another European power conquers Rome. In the future it could return but rather than be Rome be named Italy. This to prevent having a somewhat ancient collapsed civilization becoming a modern one after returning its like having Babylon come back and take over turkey... Another thing that would apply to Rome that i think should be added is. If for example rome has expanded to its historical borders and the capital is captured or destroyed then the empire will abandon that area and relocate in the farther stretches of the empire like Rome is taken and the empire dissolves to the byzatnie area without the Italian peninsula. Now i haven't thought about the second idea as much so it needs some work.