The Decapolis Cities were a group of ten cities on the fringes of the Roman Empire. This was never an official league, and there is some dispute about the actually cities that were included in the Decapolis, but they were notable as centres of Greek and Roman civilization in a largely Semitic region. Most of the cities were founded in the 2nd to 4th century BC following the death of Alexander the Great, and given their name after the Romans conquered the region in 63BC.
While some of the Decapolis cities remained important in Byzantine times, most were abandoned by the time of the arrival of Islam in the 7th century. Today, only Amman, built upon the ruins of the Decapolis city of Philadelphia has any modern importance. Jerash is the best preserved of the cities and a major tourist attraction. Pella and Umm Quais can also be visited in northern Jordan, but other cities are now lost to the desert and even their location is a mystery.