This paper examines the geopolitical effects of telegraphic development in the Ottoman provinces of Baghdad and Basra. Drawing from diplomatic and governmental sources from the Ottoman, British, and International Telecommunication Union archives, this paper highlights episodes of cooperation and contestation between the Ottoman and British Empires over telegraphic development in Ottoman Iraq. Overall, this paper argues that the telegraph should be viewed as a site for both the construction of Ottoman territorial sovereignty, as well as for challenges to such sovereignty in the form of British imperialism and the emerging practices of internationalism. Construction of the line to connect Constantinople to Baghdad was initiated by the Ottoman administration in 1858, with the encouragement of British officials. While the Ottomans hired British engineers to supervise the construction of the project, they ultimately insisted on self-administration of the infrastructure. Telegraph offices that were staffed by British workers, such as the one at Fao on the Persian Gulf, were to be supervised by Ottoman administrators, and the autonomy of British operators was restricted. However, despite these Ottoman efforts to assert telegraphic sovereignty, the actual power dynamic of the communications network was more complicated than the agreements portray. While British complaints over the quality of the Ottoman lines and administrative practices reflect the frustrations of a superpower which, at times, was forced to respect Ottoman territorial sovereignty, it is also clear from Ottoman complaints over British circumventions of restrictions that the British imperial aims often trumped such deference to Ottoman sovereignty. In addition, the use of an internationalist discourse on the part of both the Ottoman and British authorities—such as their citation of International Telegraph Union conventions—demonstrates the view of the telegraph network as being a shared resource, above the control of a single state. In examining the paradoxical effects of the technology, which was used to both assert and undermine Ottoman sovereignty, this paper connects the telegraph with the contradictions of the globalization of the late nineteenth century, which led to an increasingly interconnected world while also heightening awareness of national boundaries. Through examining episodes of collaboration and confrontation between the Ottomans and British over the telegraph network in southern Iraq, this paper seeks to contribute to a larger discussion on the role of technology and infrastructure in constructing the geopolitics of the late nineteenth century.