This dissertation examines the portraits of the Ottoman sultan Mahmud II (r. 1808–1839) as part of a campaign launched by the ruler and his propagandists to support sweeping reform efforts in military and civil spheres. The paintings and prints at the center of this study – to which I refer collectively as the “portraiture campaign” – are bound together by their shared use of the sultan’s idealized visage, direct gaze, and modern military uniform. I use the campaign as an acutely focused lens through which to view larger questions of shifting Ottoman imperial identity, legitimation ideology, and the role of visual diplomacy within the dynamic politics of the early nineteenth century. Chapter 1 approaches the campaign through its formal continuities with the established conventions of sultans’ portraiture. In it, I argue that it was in part the coexistence of various forms of Mahmud II’s image – dispersed through readily transportable and reproducible media on paper support – that facilitated the successful adaptation of foreign portrait conventions into the service of the Ottoman court. Chapter 2 discusses the bestowal ceremonies of the taṣvīr-i hümāyūn nişānı, a small-scale, medallion-format imperial portrait awarded in the style of a military decoration. I show how this portrait-object functioned in a manner new to the Ottoman context by evoking the memory of the sultan’s physical and spiritual presence across spectrums of viewing practice, ranging from the prescribed, semi-public setting of the bestowal ceremony itself to more intimate forms of viewing. Chapter 3 examines common programmatic elements and hierarchical protocol frequently repeated in the elaborate portrait-inauguration ceremonies held for the display of the large-format, wall-hanging taṣvīr-i hümāyūn (imperial portrait) in barracks, schools, and government offices. Chapter 4 considers a group of Ottoman-Balkan princely portraits in which the sitters wear the taṣvīr-i hümāyūn nişānı, framing it as an embedded object with the power to associate local, semi-autonomous provincial actors at the courts of Belgrade, Bucharest, and Iași with the sovereign power of the sultan in Istanbul. This dissertation provides the first examination of the component parts of Mahmud II’s portraiture campaign – the medallion-format, large-scale, and printed taṣvīr-i hümāyūn – with attention to their individual material and functional differences. It draws a significant connection between these works and related Ottoman-Balkan princely portraits, which have never before been considered within the context of the centralized campaign. By scrutinizing the archival records of new ceremonial forms in which the sultan’s portrait was bestowed or inaugurated, I show that these portraits were understood by contemporary audiences in their role as imperial propaganda supporting the sultan’s reform program. My methodology integrates the examination of ideologies of power and kingship tied to the Persianate and Ottoman-Islamic courtly traditions with art historical theories of vision popularized in the Western-European context in order to gain greater insight into how different strategies for the reception and use of portraiture were appropriated, adapted, and deployed. This new approach, which considers both established Ottoman and newly-integrated models of the visual representation of power, mirrors the blended strategies used by the sultan and his propagandists in their attempts to recentralize imperial control.