After the fall of Baghdad in spring of 1917, the Ottoman Foreign Ministry commissioned a series of studies on the legal status of provinces outside of direct Ottoman control. The Allied military occupation of Baghdad and the capture of Jerusalem forced state officials to reevaluate how the empire would be administered at war’s end. These reports examined the legal status of the Arabian Peninsula, as well as Egypt and Sudan, vis-à-vis the Ottoman state. Foreign Ministry international lawyers searched the imperial archives for treaties, maps and other documents that proved Ottoman legal claims to the Trucial Sates, Bahrain, central Arabia, Kuwait, and Aden. In the case of Egypt and Sudan, Foreign Ministry officials traced how administrative “autonomy” had functioned from the era of Mehmet Ali to the First World War. Overwhelmingly, these legal histories of Ottoman sovereignty in the Gulf and Egypt underlined how Britain had exercised various forms of political control over each region and provided an account of the Ottoman-British contest over territory that had not been under direct Ottoman administration for decades or more. Across the board, Foreign Ministry officials criticized autonomy as a method of imperial administration and viewed it as a British plot to wrest Ottoman territory from effective state control. This paper examines European imposed autonomous provinces in the Arab lands, and argued that they stimulated institutional development in the fields of international law, administrative reform, and domestic legislation. I build this argument by looking at the work and legal opinions generated by the Ottoman Foreign Ministry’s Office of Legal Counsel (hukuk müşavirliği istişare odası). By following the trajectory of Ottoman international lawyers, this paper shows that the exceptional provinces spurred the empire to learn and incorporate international law into its diplomatic apparatus, but also to domesticate autonomy from a constitutional perspective. By the 1880s, the autonomous provinces were lumped together as a type of province. Ottoman bureaucrats, international layers and subjects wrote about the autonomous provinces as a constitutional category and a feature of imperial administration, rather than a foreign imposition. The paper concludes with a brief reflection on how the legal work of empire inspired broad public interest among the empire’s subjects in international law and administrative autonomy—which, in the Second Constitutional era, would become one of the main lines of debates between political factions.