The Greek City States are one of the four Hellenistic factions in Rome Total War, the other three being Macedon, Thrace and the Seleucid Empire. The Greek Cities Are based in Modern day Greece but have numerous colonies such as Syarcuse. It's starting Cities are: Sparta (Capital), Rhodes, Pergamum, Thermon and Syracuse. Their victory conditions are: for the long campaign to control 50 regions including Latium (Rome), and for the short campaign to hold 15 regions and to outlive or distroy both Macedon and Thrace.
In actual history the Roman Republic game into contact with the Greek Cities in the 230's BC when the Romans sent envoy's to the Greeks to say they were invaiding Illyria to remove the pirate's who were living there. The greek cities later allied with Rome in the Second Punic War, and fought Philip V of Macedon, after he made an alliance with Hannibal, to keep him out of the war with Rome. Rome eventualy invaded Macedon and delclared Greece free of Macedonian influence. Rome occupied greece, and the Greek Cities requested help from the Seleucid Empire, Rome distroyed this force, and as vengeance sacked Eprius. After a rebellion Rome Sacked Corinth in 146bc and effectively conquered Greece.