Ottoman historians conventionally explain the trials and tribulations of the fifteenth century, a dramatic period of empire building, through a discussion of the social and political dynamics of the Ottoman “core lands” comprised of two provinces that cover Western Asia Minor and the Southern Balkans. The composition and nature of the sources studied so far account for the current historiography’s depiction of political figures and groups as primary agents of historical change and therefore their representation of these two provinces as the core Ottoman lands. This paper uses less tapped sources, such as waqfiyas and takes a more comprehensive and interdisciplinary approach to the formation of the Ottoman Empire by introducing religious, intellectual and artistic actors. The methods and analytical tools borrowed from architecture, the sociology of knowledge, urban and network studies and prosopography reveal the role of the third Ottoman province, the Rum centered around the northern Anatolian city of Amasya, in the empire building process. The intellectual, artistic and religious contributions of this province to the rising Ottoman world against the backdrop of political factionalism, interregional rivalry and urban-rural conflict challenges some of the key assumptions about the center-periphery relations in the process of empire building in the early modern period. The religious aspect of Amasya’s contribution to the Ottoman imperial fabric in the context of the city’s role in the urbanization, institutionalization and “Ottomanization” of marginalized -if not demonized- Halvetiye Sufi order will be the main focus of this paper. I argue that Amasya’s mystical tradition, unique private land-ownership practices, and privileged connection with the Ottoman center translated into a shared architectural design in religious structures. Besides, the city of Amasya, by transmitting the Halvetiye Sufi order from geographical and political margins to the imperial center in both ideological and physical sense, exerted a certain degree of agency in the making of the socio-religious scene of Istanbul, the burgeoning heart of the body Ottoman.