Except for Damascus, the Decapolis cities were by and large founded during the Hellenistic period, between the death of Alexander the Great in 323 BC and the Roman conquest of Coele-Syria, including Judea in 63 BC.
The Decapolis cities (a ten-city Greco-Roman federation, or league, created under Pompey about 64-63 BCE).
During the Greco-Roman period of influence, a number of semi-independent city-states also developed in Jordan, grouped as a Decapolis including: Gerasa (Jerash), Philadelphia (Amman), Raphana (Abila), Dion (Capitolias), Gadara (Umm Qays), and Pella (Irbid).