In this thesis, Hagia Sophia in Istanbul is handled as a living monument in its physical and cultural context in the Historic Peninsula to question the existence of a correlation between the changes in the building scale and transformations in a larger physical and cultural context. In order to do this, urban and architectural scale studies on the Historic Peninsula and Hagia Sophia are cross-read to highlight Hagia Sophia as the center of a continuously changing physical and cultural context which is changing with its transforming environment and, at the same time, changes its context through conversions that occur in the building scale up to the Ottoman conquest in the fifteenth century. This survey reveals Hagia Sophia as one of the most important architectural monuments in the world that has been a continually transforming edifice to remain in use for different civilizations in a synchronously changing urban context. The importance of the urban context of Hagia Sophia has had a major share in the maintenance of the building’s importance. Changes and continuities in Hagia Sophia, in their turn, had their share in the maintenance of the importance of the building’s urban context in a larger scale in a palimpsestic process.