Struggling to rule the independent-minded cities of Ionia, the Persians appointed local tyrants to rule each of them. This would prove to be the source of much trouble for the Greeks and Persians alike. In 498 BC, supported by troops from Athens and Eretria, the Ionians marched on, captured, and burnt Sardis. However, on their return journey to Ionia, they were followed by Persian troops, and decisively beaten at the Battle of Ephesus. This campaign was the only offensive action taken by the Ionians, who subsequently went on the defensive. The Persians responded in 497 BC with a three-pronged attack aimed at recapturing the outlying areas of the rebellious territory, but the spread of the revolt to Caria meant the largest army, under Darius, moved there instead. While at first campaigning successfully in Caria, this army was wiped out in an ambush at the Battle of Pedasus. This resulted in a stalemate for the rest of 496 and 495 BC.