In scholarship on Portugal’s Geração de 70 , Antero de Quental (1842-1891) is commonly remembered as the group’s intellectual guide or as a poet, with his sociopolitical prose unfortunately receiving less attention. This paper will propose iberianism – an intellectual current that advocates closer ties between Portugal and Spain – as an organizing principle of Quental’s prose, with his iberianist commitment evolving from an early advocacy of an Iberian federation through an interest in a common “peninsular race” and a defense of the beleaguered First Spanish Republic (1873-1874), to more fatalistic reflections on prospects for Spanish-Portuguese union. I will present Quental’s position in relation to earlier iberianists (J. F. Henriques Nogueira) and federalists (P.-J. Proudhon), and will analyze Quental’s Causas da decadência dos povos peninsulares (1871) as a transitional text in the author’s evolving iberianism.