victory over the allied greek states at the famous battle of thermopylae allowed the persians to burn athens (which had been evacuated) and overrun most of greece. however, against the combined greek fleet, the persians suffered a severe defeat at the battle of salamis. the following year, the confederated greeks went on the offensive, decisively defeating the persian army at the battle of plataea, and ending the invasion of greece by the achaemenid empire.