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).
Gerasa had its own bishop—still today it is a Titularbistum—and bishop Placcus (or Plancus) participated in the Council of Chalcedon.