And these rebellions, in 498 BCE, the rebels are able to take over and burn down Sardis, which is under Persian control. The Persians under Darius are not happy about this. So they send a force to take back control, and also to get a little bit of revenge. Because when the rebels were able to take over Sardis, they had help from some of their Greek brethren. And it's important to note that the Greeks weren't some type of a unified state. They weren't a unified empire like the Persians were. They were a fragmented group of city-states.