>>508826585 (OP)Empires/powers are just ideologies which emanate from a capital city under a based ruler who founds a dynasty.
Sometimes cities develop something which gives them an edge, and their culture/tech just spreads until things collapse under their own weight. Then the same thing will happen elsewhere.
Alexandria, Cairo, Nineveh, Assur, Babylon, Jerusalem, Petra.... All great cities which were once the centre of their worlds. A fascinating part of the world, desu.
It seems that when a city has 'made it', it never returns to greatness. I guess the inhabitants run out of hunger and desire and become content with the tales of old.