This chapter reassesses the monarchical project of Orelie-Antoine de Tounens in Araucanía and Patagonia (1860–1878), situating it within the transatlantic monarchist currents of the nineteenth century. Far from being a mere eccentricity, the iniative is framed within debates on constitutionalism, Indigenous self-determination, and European imperial expansion. The text explores how some Mapuche communities viewed constitutional monarchy as a means to preserve their autonomy in the face of Chilean and Argentine republican encroachment. It also examines the symbolic and legal strategies employed by De Tounens to legitimize his reign. Ultimately, this chapter argues that this episode forms part of a broader trend of constructing “royal nations” in postcolonial and fragmented contexts.