So, since the Persians always get painted as such bad guys concerning their war with Greece in the 400s BC, I thought I’d just take a moment and set the story straight– or well, a little straighter at least.
First off, it was the Athenians who (turns out, stupidly) drew Persia’s attention to themselves. Athens sent ambassadors to Persia to ask for its help in beating-up the Spartans if the Spartans were to try anything untoward in Athens’ general direction. The Persians then actually gave Athens what they wanted– they agreed to protect them. However, Persia imagined coming to Athens’s aid, if needed, as a father protects a son– or rather, as a superior State protects a client State. In other words, if Persia was going to protect Athens, it expected Athens’ loyalty.
Meanwhile, it was the Lydian king Croesus who first conquered the Greek city-states of Asia Minor. The books are unclear as to the ancestry of Croesus. I’m not sure if he was Lydian or Greek by race and/or culture. Supposedly, he at least once consulted the Delphic Oracle in Greece, which leads me to believe that he was at least culturally Greek. Anyway, Croesus, a little too full of himself, decides to take on the Persian Empire next. He gets his butt whipped, and the Persians take control of all those Greek city-states in Asia Minor which Croesus had recently and conveniently bagged together.
When some of the city-states in Asia Minor then ask for Greek aid in their rebellion against their new Persian overlords, Athens decides, apparently, that to offer such aid would be an EXCELLENT foreign policy move, and so they help them out. But of course, the Persians are, like, WTF? Didn’t you backstabbing Athenians just make an alliance with us?
So, the Persians come over to teach Athens how to better respect its superior ally. Only things don’t go so well for the Persians, and after two major series of engagements (490, 480-79 BC), the Persians find themselves unable to subdue the Greeks, and return home.
Greece is then free to continue developing philosophy, democracy, and an exceptionally destructive set of rivalries and antagonisms between the different mainland city-states.
Sources: Ancient Greece by Thomas R. Martin; Ancient Greece: Everyday Life by Robert Garland