The name given to the Levant by the Arab conquerors was Aš-Šām "The North". The region at the time of conquest was part of the Byzantine Diocese of the East, populated mostly by Monophysite Christian peasants (like the Mardaites) who constituted the bulk of the native population, Greek Orthodox Christian minorities called Melchites or Rûm (which in that particular context means "Eastern Roman" or "Byzantine"), and by Ghassanid and Nabatean Arabs, besides various non-Christian minorities (Jews, Samaritans and Ismaelite Itureans). The population of the region did not become predominantly Muslim and Arab in identity until nearly a millennium after the conquest.
Following the Muslim conquest, Muawiyah ibn Abu Sufyan (602–680) of the Banu Umayya governed Syria for twenty years and developed the province as his family's powerbase. Relying on Syrian military support, Muawiyah emerged as the victor in the First Fitna (656–661) and established the Umayyad Caliphate (661). During Umayyad times, al-Sham was divided into five junds or military districts. The initial districts were Jund al-Urdunn (Jordan), Jund Dimashq, Jund Hims, Jund Filastin and. Later, Jund Qinnasrin was carved out of part of Jund Hims. Under the Umayyads, the city of Damascus was the capital of the Islamic Caliphate and Syria formed the Caliphate's "metropolitan" province; likewise, the elite Syrian army, the ahl al-Sham, formed the main pillar of the Umayyad regime.
Syria became much less important under the Abbasid Caliphate, which succeeded the Umayyads in 750. The Abbasids moved the capital first to Kufa and then to Baghdad and Samarra in Iraq, which now became the most important province. The mainly Arab Syrians were marginalized by Iranian and Turkish forces who rose to power under the Abbasids, a trend which also expressed itself on a cultural level. Under Harun al-Rashid (r. 786–809), the northern parts of the province were detached to form a new jund, called al-'Awasim, which served as a second line of defence against Byzantine attacks, behind the actual frontier zone of the Thughur.
From 878 until 905, Syria came under the effective control of the Tulunids of Egypt, but Abbasid control was re-established soon thereafter. It lasted until the 940s, when the province was partitioned between the Hamdanid Emirate of Aleppo in the north and Ikhshidid-controlled Egypt in the south. In the 960s the Byzantine Empire under Nikephoros II Phokas conquered much of northern Syria and Aleppo became a Byzantine tributary, while the southern provinces passed to the Fatimid Caliphate after its conquest of Egypt in 969. The division of Syria into northern and southern parts would persist, despite political changes, until the Mamluk conquest in the late 13th century.