Syria is on the border with Parthia and thus had a large garrison of several legions just in case the Parthians became problematic. The governor of Syria was thus a big deal because he commanded around four legions at any given time. Also Antioch was one of the ends of the great silk road from china and was the great entrepôt of all oriental trade in the Mediterranean, chiefly silk, bringing great wealth to the province. Thus it was a place from which the Romans extracted large amounts of tax revenue and was very important. Antioch is also the seat of the Patriarch of Antioch, one of the five great Sees of Christianity alongside Rome, Alexandria, Jerusalem and Constantinople.

Syria was extremely rich, containing extremely important cities such as Antioch, Tyre, Sidon, Damascus, and kind of sort of Palmyra. The largest surviving Roman temple by quite a bit is Baalbek, in Roman Syria. The region had an exceptionally long history of urbanization and literacy, and as such Antioch was one of the centers for learning in the Roman world.