The present name is a corruption of Paneas, signifying a place sacred to the god Pan. The Jordan is by far the most important river in the region, and in antiquity a spring in the large cave was one of its principal sources. Little wonder, therefore, that it became a place where a nature god was venerated. Today, because of seismic movements, the water bursts (20 m3 per second) from a crack below the cave.
The Seleucids of Syria defeated the Ptolmies of Egypt here in 200 BC to assume control of Palestine. The Maccabees and their successors the Hasmoneans never conquered the district. In 20 BC the emperor Augustus gave it to Herod the Great, who in gratitude dedicated to his patron a temple of white marble near the spring. On his death the area passed to his so Philip, who in 2BC built here the capital of his territory, naming it Caesarea. To distinguish it from the coastal Caesarea, it became known as Caesarea Philippi, but the name that took root was Caesarea Paneas (Pliny, Natural History 5:71). According to Josephus, this Philip conducted the first experiment to determine the true source of the Jordan. He had chaff thrown into the circular volcanic lake Berekhat Ram, and it appeared at Paneas (War 3:512-13). In fact there is no connection between the two; an adroit courtier ensured the verification of the royal hypothesis!
Somewhere in the vicinity of the city Jesus promised Peter that he would be the rock on which the church would be built (Matt. 16:13-20). Agrippa II further enriched the city and tried to name it after the emperor Nero (AD54-68) but the new title did not take. The amenities of the city were such that Titus spent a long time here celebrating the capture of Jerusalem in AD70. A continuing Jewish present is attested in the C2-C3. Christianity was well established by the early C4.
Source: The Holy Land by Jerome Murphy- O’Connor