Okay, but here me out. What if all the soldiers of Thebes (the kinda coolish Greek one, not the hella coolish Egyptian one) were just the teeth of dragons, and they fought one another until only the strongest survived, and then those survivors became a middling city state that still got Spartans to STFU about being based at long last?
Nah, founding can only be done by one person unless you have paper to do it with (like the Founding Fathers), so chances are they fought to the death first