Invention of new weapons/gases was HUGE, but Disease and famine was also a large factor
The Mediterranean Sea separated the Greek islands. These islands grew into separate city-states as they were separated by the sea.
The hills and mountains in Greece separated the individual city-states. These cities were separated by these hills and mountains, which led to them developing into different city-states.
They will be a lot of pollution in the air and there will also be a lot of traffic
According to History it was a kamikaze. Japanese for divine wind. Works of fiction say it was hurricane or typhoon. But I would not call that a person.
The war was actually super significant, and there wasn't a singular person that actually prevented the conquest. To my knowledge anyway.
