The Ancient Greek WarsThe Ancient Greeks formed alliances like no civilization before them. This massive assembly of city-statesled to the existence of massive armies that were more coordinated and powerful than anything the world had ever seen. Here are five of the ancient Greek battles that forever changed the course of human culture:The Battle of Marathon, 490 BCThe Battle of Marathon, took place during the first Persian invasion of Greece, was fought between the combined forces of Athens and Plataea against King Darius’ Persian army. Darius attempted to invade Greece after the Athenians had sent aid to Ionia to help with their revolt against the Persians. After effectively shutting down the revolt, the angry king turned his attention to Greece, first capturing Eretria,then sailing into Marathon for vengeance. Though heavily outnumbered, the Greek forces managed to defeat the lightly armed Persian army after only five days. The Battle of Marathon was significant because it proved to the world that the Persians could be defeated.