The mighty Persian empire under Darius I is ready to avenge past wrongs done to it by the tiny city-state of Athens. Darius sends an overwhelming force commanded by Datis to destroy Athens. But, a former Persian conscript, Miltiades, persuades the Athenians to do battle with the Persians and resists their onslaught. After the Battle of Marathon in 490 B.C, the Persians return home with yet another insult from Athens.