The article focuses on the actions of the High Council for Immovable Historic Works and Monuments (HC), which was active from 1951 to 1983 as the sole decision-maker in issues of historic preservation for all historic structures and sites in Turkey. The HC archives reveal a historical and political framework for understanding the context within which the HC operated. Expert knowledge, especially in the conservation of historic cities, has been a powerful instrument, although the use of this instrument depended on the political context. The HC extended its authority in the 1950s, operating under a conservative autocratic government. In the 1960s and 1970s, on the other hand, when central power was lacking and society was dominated by political violence, chaos and economic instability, the HC could reinforce and exercise its power to raise standards in historic preservation in line with the international conservation movement.