What was common between the Ancient Greeks and Ancient Persians?

After the Achaemenid Empire (Persians) conquered the Ionian Peninsula (present-day Turkey) in 545 BC, warfare was common between Greece and Persia.  The incursion of the Satrap in lands where Greek city-states were located precipitated a fifty-year conflict between the two ancient civilizations.  In 499 BC, the Ionian Greek city-states rebelled against the Persian satrap and were soundly defeated after a six-year skirmish.  The city-state of Athens marginally supported the revolts.  This action angered the Persians.  In 490 BC, Darius set his sights on Athens.  The Greeks stopped the Persians at Marathon and Darius died shortly thereafter.  His son Xerxes attempted to avenge his father's failure.  This attempt turned out to be futile and the Greeks expelled the Persians from all Greek territories.  The Greeks and Persians eventually met again under the Macedonian king Alexander the Great.  In this confrontation, the Greeks finally and completely destroyed the Persian Empire.