The conversion of the eastern roman empire to Christianity marked a new era in the history of the near east. After c. 415 Syria Coele, the name of the region that was inherited from the Roman empire was further subdivided into Syria I (or Syria Prima), with the capital remaining at Antioch, and Syria II (Syria Secunda) or Syria Salutaris, with capital at Apamea on the Orontes. In 528, Justinian I carved out the small coastal province Theodorias out of territory from both provinces.
The region remained one of the most important sources of both wealth and ideological support to the Byzantine Empire. Massive sanctuaries were built to honor the graves of the Syrian Christian hermits, monks and early martyrs. In the 4th century, the city of Resafa became a pilgrimage town for Christians coming to venerate Saint Sergius, a Christian Roman soldier said to have been martyred in the city during the Diocletianic Persecution. A church was built to mark his grave, and the city was renamed Sergiopolis. it became, after Jerusalem, "most important pilgrimage center in Byzantine Oriens in [the] proto-Byzantine period.
The Byzantine era in Syria was put to an end following their defeat in 631 at the battle of Al Yarmouk by the Muslim forces of the Rashidun Caliphate.
The ruins of the Dura-Europos church, dating from the first half of the 3rd century are concrete evidence of the presence of organized Christian communities in the Aramaic-speaking area, far from Jerusalem and the Mediterranean coast, and there are traditions of the preaching of Christianity in the region as early as the time of Saulus of Tarsus, better known as the Apostle Paul, who was converted on the Road to Damascus and emerged as a significant figure in the Christian Church at Antioch from which he left on many of his missionary journeys.
The Syriac church represents a distinctive branch of Eastern Christianity, whose formative theological writings and traditional liturgy are expressed in the Classical Syriac language. Along with Greek and Latin, Classical Syriac was one of the three most important languages of the Early Christianity. It became a vessel for the development of a distinctive Syriac form of Christianity, that flourished throughout the Near East and other parts of Asia during the Late Antiquity and the Early Medieval period, giving rise to various liturgical and denominational traditions, represented in modern
