Theologian and scholar of history (b. 15 March 1918, Yenice village / Gelendost / Isparta - d. 17 November 1999, Ankara). He attended Yeniceköy Primary School (1931), Ankara Gazi High School (1936) and graduated from Ankara University, Faculty of Language History and Geography (1940). In the same year, he entered the faculty that he graduated from as Professor Fuat Köprülü’s assistant and two years later he completed his PhD. After his military service he was not able to return to the same institution due to the law of the time and he was appointed to Ankara University as a library specialist. One year later he became the Head of Ankara University, Faculty of Law Library. When the Faculty of Theology was established in 1949, he entered as an assistant. He became assistant professor (1953) and professor (1960) here. In the same year he was selected as the Dean of the Faculty of Theology and when he had completed his first tenure, he was selected again for two years. In addition to serving as dean, he worked as the Vice Rector at Ankara University for about nine months. He also served as the President in the Chairs of Islamic History, Religious Sects, Islamic Law and Turk Islamic Literature. (1960-79)
Çağatay also served as Rector of Konya Selçuk University between the years 1979-81. After working at the Ankara Faculty of Theology for a while, he was transferred to the Institute of Higher Education. He was invited to New York Columbia University where he gave lectures to PhD classes in the 1966-67 academic semester.
His articles were published in various newspapers and reviews especially in DTCF, Tarih Vesikaları, A.Ü. Hukuk Fakültesi, A.Ü.İlahiyat Fakültesi. He wrote entries for İslâm Ansiklopedisi (Islamic Encyclopedia) and Türk-İslâm Ansiklopedisi (Turk-Islam Encyclopedia). Some of his articles were published in some collaborative books. He held conferences in Germany, France, the United States, Pakistan, India etc. and presented papers at scientific conferences. He also gave lectures as a guest professor in these countries. His grave is in the village where he was born. Çağatay, who spoke Arabic, Persian, English and French, was married with four children.
RESEARCH-STUDY: Osmanlı İmparatorluğu'nda Reâyadan Alınan Vergi ve Resimler (Taxes and Fees taken from the Public in Ottoman Empire, 1947), İslâmdan Önce Arap Tarihi ve Cahiliye Çağı (Arabic History Before Islam and the Age of Ignorance, 1957), İslâm Mezhepleri Tarihi (History of Islamic Sects, with İ. A. Çubukçu, 1965), Türkiye'de Gerici Eylemler (Resistance Against Modernity in Turkey, 1982), 100 Soruda İslâm Tarihi (Islamic History in 100 question, 1972), Bir Türk Kurumu Olan Ahilik (A Turkish Organization: Akhism, 1974), Güncel Konular Üzerinle Makaleler (Articles on Contemporary Topics, 1994).
In addition to these, he did translations.