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.
The vast majority of the present-day Turkish people are Muslims and the most popular school of thought is the Hanafite madh'hab of Sunni Islam according to the KONDA Research and Consultancy survey carried out throughout Turkey in 2007. The Hanafi madhhab was the official school of Islamic jurisprudence espoused by the Ottoman Empire and a 2013 survey conducted by the Turkish Directorate of Religious Affairs indicates that 77.5 percent of Turkish Muslim identify themselves as Hanafis.
Although the Maturidi and Ash'ari schools of Islamic theology (which apply Ilm al-Kalam or rational thought to understand the Quran and the hadith) have been the dominant creeds in Turkey due to their widespread acceptance and propagation since the beginning of the Ottoman Empire, the Sunni creed has seen increasing acceptance.
Relations between the Sunnis and non-Sunnis in Turkey have been described as one with battle lines drawn. Refutations of Sunni and other anti-Sunni material have gone out print of favor. The discord between them has gone to the extent while Sunni's infiltration of Turkish religious discourse has gone largely unacknowledged, concern in media and academia over the fate of the Hanafi-Maturidi tradition of Turkish Islam appears as one form of recognition of the changes taking place.
However, according to various observers, Sunnis have been usually unrelentingly aggressive to devotional anti-Sunni practices arguing that anti-Sunni is irreconcilable with true Islam.