At the dawn of the fifth century BCE, Persia stood triumphant. For more than five decades her warriors had crushed all who opposed them. No city had ever withstood a Persian siege, and all the armies of the known world's most powerful civilizations had met their ruin trying to halt Persia's inexorable march of conquest. The dreaded Persian army finally arrived in Greece, and the Athenian hoplites wondered how they would be able to resist an army of professional warriors three times their size. However, the Athenians proved victorious at the Battle of Marathon, changing the course of history and defining the tenuous relationship between East and West for centuries to come.