We have no definite records concerning the foundation of Hierapolis, but the tradition that it was founded by the Pergamenes would appear to be reliable. 190 B.C. There is no definite proof of the existence of a settlement on this site in more ancient times, but it seems u unlikely that such a remarkable site should have been left uninhabited. By that time Cydrara had already disappeared. The written history of Hierapolis begins with the Roman period. As a result of the transfer of the Kingdom of Pergamon to Rome in accordance with the terms of the will left by Attalos III, Hierapolis came under Roman rule in 129 B.C. as part of the province of Asia.
Later records are chiefly concerned with a series of earthquakes.
The city was devastated by an earthquake which took place in 17 A.D. during the reign of Tiberius, but the most severe of all the earthquakes occurred in 60 A.D. during the reign of Nero. The present appearance of the city probably results from the reconstruction after this earthquake carried out with the financial assistance of the Emperor. No events of note are recorded in the subsequent period apart from visits to the city made by the Emperor Hadrian in 129 A.D., the Emperor Caracalla in 215 and the Emperor Valens in 370.The city received the much coveted title of Neocoros from the Emperor Caracalla. This accorded the city certain administrative privileges as well as the right of sanctuary. There were a number of Jewish colonies in Hierapolis with their own more or less independent organizations.