At the core of the politicization of Islam is the territorialization of Islamic belonging, which during the nation-building phase has manifested itself in ways previously unknown in the former Muslim Empires. This territorialization was combined with the elimination of religious and cultural diversity, leading to a specific form of religious nationalism called hegemonic. The genealogical investigation shows the conceptual and institutional changes that constitute the bedrock of the current manifestations of Political Islam from the last phase of the Ottoman Empire to the current national situations. Areas of politicization in Syria and Turkey are presented from the inception of the nation-state to today’s civil war in Syria and the role of Turkey. These areas cover the status of sharia in state law, the boundaries of the secular space, the status of political violence, and the influence of regional and transnational political and religious actors.