Nation states are formed and legitimated through homogenisation of a diverse, contested and at times mythical past, to construct a collective national memory. Historic monuments, among many other instruments of memory, have been significant devices for nation-states to represent a shared past, present and future to their citizens and to reinforce national identity. Having its roots in the late 19th century, the search for collective history and origins of Ottoman architecture and the rise of national consciousness eventually led to the idea of ‘national monument’ in the Ottoman Empire at the turn of the century. With the enactment of 1906 Antiquities Regulation, Islamic artefacts and buildings that are part of the Ottoman urban life were considered as antiquities for the first time. The regulation defined antiquities as the remnants of any civilisation that had formerly inhabited within the Ottoman territories. However a legal framework for how to preserve the monuments that are part of the Ottoman urban life was only defined by the Regulation for the Preservation of Monuments in 1912. Consequently, the Commission for the Preservation of Antiquities (Muhafaza-? Asar-? Atika Encümeni) was formed in 1915, which was responsible from the preservation of historic monuments within Istanbul and functioned as an advisory board for restoration projects. After the foundation of the Turkish Republic, the Republican authorities recognised the commission as a supervisory body for preservation activities in the old imperial capital of Istanbul. With the distancing of the secular Republic from its imperial and religious past, the Ottoman monuments were appropriated as ‘national monuments’, disassociating them from their multi-ethnic and multi-religious origins. Moreover, the antiquities were amalgamated with the nationalist historiography by being regarded as the imprints of Turkish culture throughout history and their classification such as Hittite, Roman, Byzantine or Ottoman served useful for periodisation. Within this context, the paper will focus on the role of the Commission for the Preservation of Antiquities in the institutionalisation of preservation activities in Istanbul. By presenting its negotiations and confrontations with other state actors through selected cases, the paper will discuss the Council’s contribution in recognising which inherited remnants of Istanbul’s diverse past are valued above the others as national monuments and the conservation approaches and practices it encouraged for their survival.