The book examines the history of Muslim architecture on the territory of modern Turkey from the arrival of the Turks in Anatolia in the 11th century to the establishment of the hegemony of the Ottomans in the middle of the 15th century. The focus is on the mosque, its compositional and planning principles and regional options, the process of forming a new type of hall cult building, later developed in the architecture of the Ottoman Empire and implemented in the model of the "large Ottoman mosque." Both the "main" lines of development of the mosque (Seljuk, Ottoman) and the "alternative options" of cult architecture usually remaining outside the research interests in the Anatolian principalities that existed before the formation of the Seljuk Sultanate of Rum and after its collapse are considered. For the first time, an attempt is made to demonstrate the continuity of Seljuk and Ottoman architecture as two consecutive stages in the development of Turkish architecture.