Just as every faction has a place that they started out from, there are a few core territories in which their ideology is so deeply entrenched that they simply will not tolerate another. These are the faction's home territories. If they are conquered, the people will eventually rise up in an effort to throw off their "oppressors." So ardent is their furor that the bleaker things look for the faction, the more passionate they fight. If the entire faction falls, this is where it will rise again.
When a faction's home territories are conquered, they will periodically start battles independent of the faction's High Command vote. These battles do not count against the faction's three battle limit. Additionally, they will forcibly end existing battles in the territory, skipping the cooldown period and immediately creating a new battle against the occupying faction. This ensures that, even if the faction holds no territories, it will always have a location to fight from.