Located at the crossroads of various trading routes since the second millennium B.C., Aleppo has been inhabited by the Hittites (2400 BC to 1600 BC), Fatimids, Seljuqs, Mongols, Mamluks, and Ottomans.
From the earliest years to 1130, the Nizaris Ismailis operated from Aleppo and subsequently from Damascus. The first Nizari Ismaili dais from Alamut arrived in Syria at the beginning of the twelfth century.
The dais established the dar al-dawa (house for preaching) and Aleppo became their centre and base for further activities. The diversity of Syria’s religious topography contributed to the spread of the Nizari dawa.
By the middle of the twelfth century, the Nizari Ismailis succeeded in acquiring a network of strongholds in Syria including Qadmus, Kahf, and Masyaf, their most important stronghold which usually served as the residence of the chief dai.
The fortress of Masyaf is currently being restored by the Aga Khan Trust for Culture.
— Farhad Daftary The Ismailis Their history and doctrines (Cambridge University Press, 1990)