They ceased fighting each other to unite and repel Persia, and then when a peace treaty with Persia was established, went back to their usual fighting each other with increased ferocity.
The Greek and Persian War started in 499 B.C.
Which particular war? The Persian what?
First define the First Persian War. The Persian War ran 499-449 BCE - it had several phases - Ionian Revolt, Persian punitive expedition against Eretria and Athens, Persian invasion of mainland Greece, Greek counter-offensive. Which among this is supposed to be 'First Persian War'?
Many were left husbandless and fatherless. They were looked after by their relatives as was customary.
It was between an alliance of Greek city-states and the Persian Empire. Today we call it the Persian War to differentiate it from the wars between the Greek city-states. It is often called the Greco-Persian War.
It allowed the Greek city-states to return to their usual activity of fighting each other.
Not at all. The war began when the restive Greek city-states within the Persian Empire revolted.
The Persian Empire and a coalition of Greek city-states.
The Persian army, and the armies of the Greek city-states.
The Persian thought the Persian Empire. The coalitions of Greek city-states thought the coalitions of Greek city-states.
The Greek city-states in Asia Minor revolted against rule by the Persian Empire.
The war between the Greek city-states and the Persian Empire 499-449 BCE.