This episode explores the Battle of Marathon in 490 BC, contrasting the historical reality of the conflict with the modern myths it inspired. It details how a vastly outnumbered Athenian army utilized a brilliant tactical gamble to defeat the Persian Empire, ultimately securing the future of Western civilization. Beyond the military strategy, the source examines the Ionian revolt as a catalyst for the invasion and the political motivations of the Athenian democracy. It also deconstructs the legend of the lone runner, revealing that the modern marathon race is actually a romanticized blend of different historical events. Ultimately, the text illustrates how this singular day shattered the aura of Persian invincibility and launched the Golden Age of Athens.