Traditionally the city was founded by the king of Pergamon Eumenes II. In the second half of the 2nd century B.C. Hierapolis passed to the Romans as provided for in the testament of Attalus III. The emperors took good care of the city, which was known for its baths and miracle-working hot springs. In 17 A.D. a terrible earthquake razed it to the ground but reconstruction soon began under 

Tiberius. The city flourished under the emperors who followed and the new Christian doctrine also found a fertile terrain thanks to the apostolate of Philip who was martyrized here in 80 A.D.

The Roman Theatre was built in the 2nd century A.D. and is still basically in good condition despite the collapse of much of the proscenium and the frons scenae. The cavea, which is set against the hillside, once had a seating capacity of 25,000 and is still used for representations in the Festival of Pamukkale.

The Baths, erected most probably in the 2nd century A.D., are in a good state of preservation

Other remains in this archaeological zone which merit attention include the so-called Martyrium of St. Philip, built in the early 5th century on an octagonal ground plan to house the mortal remains of the saint who was martyrized here during the persecutions ordered by Domitian. Outstanding in the list of attestations of Roman times in Hierapolis is the so-called Arch of Domitian, an imposing gateway with three passageways erected under Julius Frontinus who was proconsul in the Anatolian province in the 1^st centruy A.D. Beyond the arch, before reaching the last necropolis, the ruins of a bath structure dating to the 2nd-3rd century A.D. can be distinguished. It was later converted into a church (5th cent.). The Necropolis is one of the most extensive of its kind in all of Turkey. The burial grounds, which stretch out for almost two km. On either side of the way, contain an impressive number of tombs of various types and periods. Tumulus tombs, sarcophaguses and actual mausoleums date from the late Hellenistic to the Byzantine period.