The Hellenistic theatre probably dates from the second century BC.

Euromos was the most important city in Caria after the neighbouring town of Mylasa (today Milas), about ten kilometres away. In the middle of the 5th century B.C. Euromos was a member of the Delhi-Atttian Sea Alliance. According to a local plaque, the name of the city in the 5th century BC was "Cyramos" or "Hyramos".
King Maussolos II, known by the mausoleum of Halikarnassos named after him as the Wonder of the World in Antiquity, probably contributed to the strengthening of the town in the 4th century BC with his Hellenization policy.

Euromos seems to have retained its independence until the neighbouring town of Mylasa rebelled against Greek Rhodes in 167 B.C. and subsequently took control of the territory of Euromos.
Euromos formed alliances with the Roman Empire, Rhodes, and the Carian city of Iasos, growing and flourishing in Hellenistic and Roman times.