In 636A.D. Syria was again conquered, this time by the Arabs, and became part of the fast-growing Islamic Empire. Damascus became the capital of the Umayyad dynastic empire, when it was the seat of several powerful Umayyad caliphs. Rule by another Muslim dynasty, the Abbasids, followed.
By the end of the 11th century, the Crusaders had arrived in the region and incorporated part of Syria into their Christian Kingdom of Jerusalem. When Salah al-Din (Saladin) defeated the Crusaders, he took Syria and overthrew the Kingdom of Jerusalem at the end of the 12th century.
Syria was then ruled by the Mamelukes and, after 1516, became part of the Ottoman Empire, which held fast until the beginning of the First World War. At that time, an alliance between Britain, France and the Arab people resulted in the expulsion of the Turks from Syria.
Strong nationalist movements emerged in many parts of the Ottoman Empire during the early years of the 20th century. When World War I (1914-1918) broke out Turkey took the side of the Central Powers. The Allies gave the Arabs hopes of postwar independence in order to enlist support against Turkey. In January 1916, by the terms of letters between the British government and Husein ibn Ali, grand sharif of Mecca, the latter promised Arab participation in the war on the Allied side in return for a British guarantee of independence for all Arab lands south of a line roughly corresponding to the northern frontiers of present-day Syria and Iraq. In May of the same year the United Kingdom and France secretly concluded the Sykes-Picot agreement, by which most of the Arab lands under Turkish rule were to be divided into British and French domains of influence. The areas comprising present-day Syria and Lebanon were given to France, according to the agreement, while Palestine and Jordan were assigned to the United Kingdom.