How the wars happen This how the wars happen because the Persian Empire had all of the fertile Crescent and Asia Minor. A lot of Ionian Greek revolt against the Persian Empire. The Persian Empire want them to bring him earth and water.
The Battle of Marathon Darius sended a huge Persain army, across the Aegean to have his troop. His troop landed at the Marathon.
Battle of Thermoplylae Thermoplylae went fought the Sparta. The Greek force was very small determined to make a stand against the huge persian army.