The topic of this thesis is the analysis of the role of the old turkic religion in the construction of the national identity of the Republic of Türkiye. Nationalist ideas in the Ottoman Empire first appeared among non-Muslims, and as a result, separatist tendencies as well. This, in turn encouraged then Ottomans to think about their nationality (Gökalp & Berkes, 1959). There are many works written before and after the fall of the Ottoman Empire about the identity crisis of the Ottomans. One has to be cautious while researching about, and using the term “identity” due to the various theories and definitions on this subject. For A. Smith, national identity according to the Western model is based on historical territory, legal-political community, legal-political equality of members and common civic culture and ideology (Smith, 1993). The central question of this paper was whether the old religion of the Turks, which was practiced in Central Asia, influenced the construction of national identity, and if so, to what extent. With the fall of the Ottoman Empire and the negation of the Ottoman legacy that followed, the new government was tasked with constructing a new identity that would not be burdened by the mistakes of its predecessors. Following that trail of thought, question arises as to who the Turks really are and what makes Turks Turks. At that point, many, including Atatürk himself, turn east towards their ancestral homeland. For example, Atatürk had made the Alevis into a symbol of "guardians of authentic Turkish pre-Islamic traditions", which at the same time confirmed them as the "true" Turks (Procházka-Eisl, 2016). This is one of the indications that old beliefs played a certain role in the construction of national identity, but the question remains to what extent. The aim of the thesis is to first recognize the elements of the old religion of the Turks and then to assert their role in the construction of the national identity of the new secular republic. For this purpose, the works published in the period of the late Ottoman Empire and the first decades of the Republic were analyzed. The analysis shows the extent in which elements are represented in school literature and published works as well as the way they were utilized. For example, how critically were they approached, whether they were written for ideological, educational or scientific purposes, whether they were based on the research and such. In addition, relevant literature was consulted regarding theoretical frameworks and contextualization of the analyzed works. Applying the theoretical assumptions of culture and identity, and the anthropology of social memory, the research touches on the treatment of this topic in Turkish historiography and the way Turkish authors approach it. As can be seen from the above mentioned, the methodology consists of text analysis and critical reading of relevant sources. The first part of the paper gives a brief overview of the Turkish homeland in Central Asia, and the historical context of the collapse of the Empire and the establishment of the Republic so that the reader can understand the historical background of the development of Turkish nationalism. The next step was to build a theoretical framework on which to base the analysis that forms the central part of the paper. The paper finishes with the conclusion that presents the results of the analysis and answers the research questions.