The paper is largely theoretical, supported by data on conversion to Islam in the Balkans from secondary and primary sources. The paper proposes a theoretical framework connecting religious conversion with the evolution of the Ottoman imperial formula, based on the dichotomy between social homogeneity and complexity. It argues that the Ottoman imperial model emerged in the inclusive environment of late 13th century Asia Minor and became firmly established by the middle of the 15th century by converging the multiple sociopolitical units it absorbed upon a new cultural norm upheld by the ruling institution. The role of the Ottoman elite in maintaining this “unity of complexity” was crucial. The paper also argues that one of the benchmarks to evaluate changes in the original imperial model is conversion to Islam. Based on that criterion, the original imperial model continued to be the main political paradigm through the first half of the 17th century. Respectively, conversion to Islam in the Balkans picked in the 17th century. The emergence of fundamentalist powers in the second half of the 17th century and regionalization of the Ottoman political elite in the 18th, however, seemed to have changed the model to be less inclusive. As a result, conversion to Islam in the Balkans largely stopped in the first quarter of the 18th century. The paper concludes that the victory of the centralist powers at the beginning of the 19th century over the ayans should not be interpreted as a re-establishment of the original Ottoman concept but rather as the opposite—as a victory of a new political model, which emphasized the “unity of homogeneity” over the “unity of complexity.” The paper also raises the question, whether that change may have also triggered a native to the Balkans proto-nationalistic development that parallels the development of western nationalism, put precedes the latter’s dominating influence in the 19th century.