The Region of the Ten Cities in today's Syria, Jordan and Israel
were merged according to the current state of knowledge, at the latest around 63 BC., from the Hellenistic Cities founded between the 3rd to the 1st century BC.
Pliny the E. gave us a list of cities and we can find the clear assignment to today's places. The provided evidences of many localities shows that they were already in bloom before the centuries of Christ.
Some of them are praising themselves as Hellenistic Foundings, but they are sometimes also mentioned 1500 years earlier in war reports, or tribute payments of the Egyptian or Assyrian empire under their "original name".
Certainly not only 10 cities or "Polis" are merged within the Decapolis, this is not only explained by the different Lists, since the scriptures of Plinius the E. . The archaeological findings, the location on the roads or the Dekapolis aqueduct also help here. The most striking indications are, of course, the eras used (usually the Pompeian era) on found coins, or even inscriptions that have been preserved.
Especially the cities of this region were characterized by theaters, large public baths and water games, as well as partially 13-18m high temples. In addition to many other deities and at a later time the very early settled Christianity here, stood until this time Agathe-Tyche as Fate / Fortune and city goddess,of the Decapolis region in very high rank.
With her crown, usually depicted as a city wall, she stood like no other, for the independent "polis" of the city union.
As can be seen not only in the travel descriptions by S.Merrill, the region also thrived on its consistent water supply. Every major "community" in the region had a sophisticated water supply concept at that time. From the small aqueduct with connected reservoir, as in Er Rafid, or El Jahudije, to large aqueduct routes, as at the southwest end of the Sea of Galilee, the Luwakanal (flowing north from the Hauran), the so-called Demon Channel (flowing east from the Hauran Mountains) which supplied single castles of the Limes arabicus. Or the "Canal of Palma", (flowing westward from the Hauran), which supplied the region and places south of the trachonitis and west of the Hauran mountains with fresh water.
Also Qanawat, Dionysias and Philippopolis had there own Aqueduct Systems, also coming from the water-rich regions of the Hauran mountains known.
The longest among them, and at the same time "representing a world's unique engineering masterpiece" , was the Qanat Fir'aun named Aqueduct.
The Decapolis was not a solid entity and yet it can be shown that the area characterized by it and the Hellenistic tradition was coherent and also preserved as the main region in the successor constellations (Prov. Coile Syria).
Pliny the Elder describes Damascus, Philadelphia and Raphana are positioned against Arabia. So this Cities should describe both the maximum extent of the Decapolis region in north-south direction, as well as a furthest east-reaching area boundary. This fits very well, with the on this website from me here for the first time voiced assignment of Raphana to el Musmije or to its military predecessor settlement to Pliny's time (about 50-79 AD) with the name Ar-Rafiah in today's district of South Ghouta. See also single page "Raphana"
Except of Raphana and Dion, all Cities which were mentioned by Pliny, Eusebius, Ptolemy and Stephen v. Byzanz are today unequivocally identified. Through science, but were also repeatedly alternative locations for Canatha / Kanata (Qanawat), or Capitolias discussed.
Quotation from Pliny the Elder: "Most people, however, call Damascus, which is very fertile due to the irrigation, which is derived from the river Chrysorrhoas, which is almost completely exhausted.
Philadelphia, Rhaphana, which cities all lie to Arabia. Further, Scythopolis, which received its name from a Scythian colony, and was formerly called Nysa after Bacchus, whose nurse lies buried here.
Gadara on the river Hieromiax, the already mentioned Hippos, Dion, the water-rich Pella, Galasa and Canatha. Between and around these cities are the Tetrarchies, which, as it were, form individual districts for themselves and are considered kingdoms, namely:
Trachonitis, Paneas, in which Caesarea is located with the above-mentioned source, Abila, Arca, Ampeloessa, and Gabe. "
The list of regions between the cities of the Decapolis appears at the end of the list of Pliny.
Examining these in detail reveals a number of regions that describe a complete circle over 360 degrees.
At first "The Trachonitis", the area of Leddja, an area of ancient lava flows northeast of the Sea of Galilee, then Paneas with Ceasarea Phillipi in the north of the Sea of Galilee, after which the list extends further north and names the area of Abila, which is generally equated by science with that of Lysanias (Abilae Lysinia).
This is followed by a region of Arca, which I believe is the area on the western and southern shores of the Sea of Galilee. Due to the ancient names "Arḥa" in this area and the important Hellenistic localities at the exit of the Jordan from the Sea of Galilee, this region is the plausible Connection between the southwestern area of Scythopolis and the north and east decapolis cities. Umm el Junieh, Beit Yerah, El Kerak and the city of Philoteria located in this place (in my estimation the future episcopal city Helenopolitanus in Palestine), show by various finds, among other things of city deities (Agathe-Tyche, usually depicted with city wall crown), their importance in Hellenistic times. The Emperor's mother Helena, who made various foundations here later on the Sea of Galilee, gave the Diosese Helenopolis the name.
For the sake of completeness, the localized Arca (Archais) should be mentioned further south in the Jordan Valley for this area.
In the list of Pliny follows now, the mostly neglected Ampeloessa (the Vineland /region of the vineyards / rich of Grapes)which i localize southeast of the Sea of Galilee. In my estimation the association with Abila at Wadi Queilbeh and its surroundings up to Beit Ras (Capitolias) would be very correct here. This would also plausibly explain the long-discussed omission of the "Abila of Dekapolis". Numerous artifacts, as well as old and new maps testify the ancient wine growing, for instance also the Names plain of viticulture "Ard el Karm" , or the Vineyard Karm ash Sheikh called mountainside. Furthermore, terms such as Winepress Kelter etc. can also be found in old topographic locations. These entries are all in the area between Abila and Beit Ras (Capitolias).
The enumeration of Pliny concludes with the region / empire "Gabe", which is also said to be a region between the cities of the Decapolis. That these are not the places with this name in the Carmel Mountains or today's Israel, it seems clear.
In my estimation, the Gabe area was around the village of Gabia (east of the Sea of Galilee) or both owed their names to each other. Gabia, which until the 12th century was known as an important point along the main road between Damascus and the Ajlun region, and the region mentioned by Pliny was thus near the striking and high Tell el Jabiha around Sheikh Saad, the ancient Carneas.
Thus, the circle of regions closes in the list of Pliny and thus forms a consistent picture of the Decapolis region.
Repeatedly it is also becomes clear that the Decapolis region must have consisted of significantly more than the 10 named cities.
However, as was well and extensively studied by H.Bietenhard among others, the confederation was always subject to change, and so we can find within the scriptures of C. Ptolemaeus other cities, which, if properly read, may even be attributed to the later region designation of Coile Syria. For completeness, all additional places in the list are named here:
Heliopolis = Baalbek
Saana = Saana Bosana (in eastern Hauran)
Ina = Inachos = Anat between Imtan (Motha) and Deir al Kahf (Speluncae)
Samulis = Simlin / Ankhel south of Es sanamein (Aere)
Abila = Tel Abil at the Wadi Queilbeh (already indirectly called at Plinius and a capital of the region Ampeloessa)
Kapitolias = Beit Ras (already indirectly mentioned in Pliny and a capital of the Ampeloessa region)
Adra = Dera'a
Gadora (kome) = near Es salt (also according to the coordinates given at Ptolom. Northwest of Philadelphia)
So here we have a list, written about 100 years later which already contains 18 place names.
For more information on a selection of remarkable places within the Dekapolis, see here.
The following, always referring to the current satellite images, places can be interpreted as follows.
Pin in red = designation as city of the Dekapolis at Plinius the Elder.
Pin in blue = Indirect entry within the scripture of Plinius the Elder mentioned in the Decapolis region (see explanation and original text above).
Pin in red with a 2 or Violet with a 2 = These places were named both by Pliny and Ptolemy and others.
The limit of the Dekapolis, coarsely drawn up by me, includes the associated areas of the cities and shows that in the approximately 100 years between the description of Pliny and Ptolemaeus, only small extensions have taken place.
The 2nd Kanata (probably today's Kerak) is also noted, no matter of Pliny the Elder meant this, or today's Qanawat, the Kerak-Village would have been also within Pliny's "Gabe" region, which I have outlined here.
For the development of the Decapolis in the same limits to the first dioceses of Christianity, compare also "The First Dioceses"