Islam in Turkey

The established presence of Islam in the region that now constitutes modern Turkey dates back to the latter half of the 11th century, when the Seljuks started expanding into eastern Anatolia. According to religiosity polls, 99.8% of the population identifies as Muslim, and only 2% is non-religious. Most Muslims in Turkey are Sunnis, forming about 78% of the overall Muslim denominations. The remaining Ithna'ashari-Shia Muslim sects forming about 20% of the overall Muslim population consist of Alevis, Ja'faris (representing 4%) and Alawites (with an estimated population of around 1 million) which is about 1% of the overall Muslim population in Turkey.

During the Muslim conquests of the 7th and early 8th centuries, Arab armies established the Islamic Empire. The Islamic Golden Age was soon inaugurated by the middle of the 8th century by the ascension of the Abbasid Caliphate and the transfer of the capital from Damascus to Baghdad.

The later period saw initial expansion and the capture of Crete (840). The Abbasids soon shifted their attention towards the East. During the later fragmentation of the Abbasid rule and the rise of their Shiite rivals the Fatimids and Buyids, a resurgent Byzantium recaptured Crete and Cilicia in 961, Cyprus in 965, and pushed into the Levant by 975. The Byzantines successfully contested with the Fatimids for influence in the region until the arrival of the Seljuk Turks who first allied with the Abbasids and then ruled as the de facto rulers.

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Wikipedia