This dissertation aims to discuss the reemergence of Charrúa people in the region adjacent to the Río de la Plata. Specifically, I will evaluate some of the means through which one of the most prominent Charrúa representations in Uruguay, the Consejo de la Nación Charrúa (CONACHA) vocalizes its claims: by participating in UN forums and in Fondo Indígena para el Desarrollo de los Pueblos Indígenas de América Latina y el Caribe (FILAC). This endeavor intends to show some of the efforts Charrúa people are undertaking in order to contest the commonly-sustained argument of their extinction as an ethnic group, which happens to be intimately coincident with national formations in the region. The dissertation is structured in three chapters. In the first one, I discuss how colonial encounters have shaped much of modern understandings of sovereignty and international relations. Further, I expand to analyze how the international regime of Human Rights is shaping and being shaped by a coordinated global refashioning of the category indigenous. On the second chapter, I evaluate Río de la Plata s regional dynamics involving colonial interethnic relations, and the national formation of Uruguay, which sustains the quality of an Indianless country for more than a century. Thirdly, after briefly exposing the history of Charrúa reemergence, I discuss analyzed speeches, claims and collective dynamics of belonging deriving from Consejo de la Nación Charrúa (CONACHA) transnational activity. By bringing together arguments made in the three chapters, I sustain that Charrúa reemergence in Uruguay may challenge political limits by unsettling the ambiguous and complicated constructions of national formation and sovereign authority in the region. Moreover, I advocate for considering the phenomena of indigenous reemergence or ethnogenesis not only as a subject of concern for International Relations, but also as a privileged locus for one to evaluate its constitutive limits, and potential fractures.