Quote Originally Posted by Kralizec
I think AI factions kept reemerging regardless of wether there was an actual underage heir- in fact I'm not sure if the AI factions track underage heirs at all or if they just spawn mature heirs out of nowhere. There's no way to know.
Well one ought to be able to check for underage heirs in other factions by using the "-ian" switch (although I myself haven't tried it).

Either way, however, it does make sense. I never have factions reappear after enough time has passed, which would reflect the fact that the last surviving member(s) of that faction's dynasty has perished (and thus there is no one left to lead that faction in a re-emergence).

Quote Originally Posted by Myrddraal
Though unrealistic, it brought challenges in the late game - always a good thing.
True dat. It was a bit cheesy, but I didn't mind faction re-emergences nearly as much as most of the other late-game stuff that was meant to slow you down.