Palaestina
The area under discussion during the early Byzantine period was a much larger area than the area known as Syria Palaestina under pagan Roman rule. while the border of Palaestina stayed the same, the areas of Negev, from Beersheba and south, the southern Transjordan, and Sinai were detached from the Arabian province (Provincia Arabia) between 295 and 300 CE and became part of the southernmost area of the three administrative areas of Palaestina. The new border between the two provinces bisected Transjordan along Wadi el-Hasa, which reached the Dead Sea at its southeast end, just north of Zoar.
The new Palaestina would consist of the three administrative areas:
Palaestina Prima, which covered the central coastal areas, the previous Judaea Palaestina, the western part of the Galilee, and Samaria.
Palaestina Secunda, which covered the eastern part of Galilee, the southern Golan, and the northern part of Transjordan.
Palaestina Salutaris (or Tertia from the sixth century), which covered parts of Sinai, the Negev, and the southern Transjordan.
Palaestina Prima
Palaestina Prima had Caesarea Maritima as its capital, which previously would act as the capital of all Palaestina. However, one of the ideas behind the reforms, which ensured the changing borders, was to decentralize the administrative areas to prevent too much power to be in the hand of the local authorities.
Of other notable cities worth mentioning we find: Jerusalem, Gaza, Neapolis, Ascalon, Raphia, Dora, Apollonia, Joppa (Jaffa), Jamnia, Azotus, Ascalon, Diocletianupolis, Constantia, Eleutheropolis, Nicopolis, Diospolis, Ono, Antipatris, Sebaste, Regio Hiericho, Regio Amathus, Regio Gedor, and Livias.
The population of Palaestina Prima primarily consisted of Christians, though there was a significant minority of Samaritans, as well as some remnants of the Jewish population which was forced to flee Judea after the rebellions in the first century and first half of the second century CE. The population was primarily Greek speaking, though Aramaic and Hebrew were spoken by the Samaritan and Jewish local population.
The population would change during the centuries under Byzantine control, with both the Samaritans and the Jews dwindling in numbers, caused by a combination of Christian aggressive proselytizing, Samaritan revolts, and a Persian invasion in the early seventh century, supported by the Jews.
Palaestina Secunda
Scythopolis (modern day Bet Shean) was the capital of Palaestina Secunda, the north-eastern part of Palaestina.
Other notable cities of Palaestina Secunda were Capernaum, Nazareth, Tiberias, Tetracomia, Diocasaria, Hippos Gadara, Helenopolis, Nain, Legio, and Pella.
During the first centuries under Byzantine rule, Palaestina Secunda had a population which consisted mostly of Jews, a large Christian minority, as well as some pagans and Samaritans. This also was the centre of the Jewish patriarchy until the fifth century, where the seat would be abolished by the Byzantine emperor Justinian I. From then on, the Jewish population would dwindle, both because of aggressive Christian proselytizing and imperial edicts against the Jews.
Palaestina Salutaris
Palaestina Salutaris, later Tertia, consisted of the Negev with Birsoba (Beersheba) as the northernmost city, parts of the Sinai Peninsula, and the southern Transjordan, with the capital being situated first in Petra and since in Elusa.
Of other notable cities we find Sobata, Oboda, Mampsis, Aelana, ,Nessana, Birosaba (Beer Sheva), Malaatha, Charachmoba, and Augustopolis.
Though the climate was more arid than the northern parts of Palaestina, it is believed that it was more humid than the case is today, which allowed a thriving production of wine, which was to become famous in the rest of the Byzantine world. The wine would typically be bottled on the Gaza amphora, which had its name after the city of Gaza from which the wine typically would be shipped.
The population consisted of Arab Christians, Ghassanids and Nabataeans, which inhabited the northern Negev, as well as nomadic tribes living further south. The area was particularly thriving during the latter centuries under Byzantine control and seem to have continued to do so during the first couple of centuries after the Islamic conquest.