This paper focuses on a little-known aspect of the first constitutional period in the Ottoman Empire: the introduction of idare-i örfiyye (an equivalent of the state of siege) into the Ottoman legal system. With a name rooted in the Ottoman legal tradition and a definition clearly inspired by the nineteenth-century French “état de siège,” the idare-i örfiyye was a case of legal hybridization that combined the Ottoman political and legal tradition with transnational (or transimperial) legal circulation. This paper seeks to understand how and why different legal references were combined in order to make it possible, under exceptional circumstances, to suspend the ordinary legal order. At the same time, it analyzes the first application of the idare-i örfiyye, which occurred during the Russo-Turkish War of 1877–1878, to show how local and diplomatic reactions to this exceptional state of affairs were crucial for the further definition of the notion. Through a critical approach to legal texts and archival documents, the article discusses how various legal sources, the political context of the early Hamidian reign, and local experiences all shaped the notion of idare-i örfiyye, soon transforming it into a tool of government for exceptional and (more frequently) non-exceptional times.