ok, suppose I'm calling the hills of western MA "mountains" then one day I visit the rockies and think "oh, THOSE are mountains" then go home and say "this is a hill not a mountain" the hills of western MA haven't changed, have they?
would be an interesting choice as the caliphate fragmented almost immediately after being established...by the 800s you already had "the caliph and those other muslim states that reject the caliph"