The Greco-Persian Wars were a series of conflicts between the highly decentralised Greek city states (which ranged from proto democracies like Athens to uber Fascist Sparta) on the one side and the Persian Empire on the other side. The Persians were liberal in at least one way, they abolished slavery but the Persians had an autocratic empire and subdued rebellions, see Persian Empire. Aside from various wars in which the Persians conquered the Greek states of Ionia, there are three wars that are still remembered today.