In 490 BC, Darius I invades mainland Greece in retaliation for the Ionian Revolt's destruction of Sardis, with Athens's aid. An advance scouting party is slaughtered by a small detachment of Athenians, led by Themistokles and Aeskylos. The following day, at Marathon, General Miltiades comes up with a radical strategy to abandon the traditional phalanx and charge the numerically superior Persian force with a battle line that has been deliberately thinned in order to allow the Greeks to flank the Persians and catch them in a pincer. The strategy works, and the Persian force is slaughtered, but Miltiades orders the army to return to Athens immediately, knowing that the main body of Darius's force is headed there by sea.