Decidedly understudied and still unavailable to Anglophone readers, Die Staatslehre des Dante Alighieri (1905) was Kelsen’s first monograph, published one year before his doctoral graduation and six years before the release of his Hauptprobleme der Staatsrechtslehre (1911). His incisive book, which would become a reference point for the study of Dante’s political thought among German legal and political theorists, offered a comprehensive, historically situated, and critical account of the Poet’s recipe for global peace: namely, a universal and – most importantly – secular monarchy capable of bringing order into a world plagued by factionalism, institutional instability, and the competing aspirations of the two universal authorities of the Middle Ages (the Pope and the Emperor). Without falling into anachronistic readings, this chapter unearths and explores Kelsen’s first book to ask whether we can discern, in the flow of its analysis, an embryonic anticipation of notions, thoughts, and frameworks that he would articulate over the following decades. It argues that Kelsen’s later work on legal cosmopolitanism and pacifism, with its critique of the dogma of nation-state sovereignty and its emphasis on the unitary nature of the legal universe (and on the primacy of international law therein), pushed in new directions two concepts at the core of Dante’s De Monarchia: the monistic construction of a legal system free of contradictions and the creation of an impartial global authority that would solve disputes among contending parties and thus ensure lasting peace on a planetary scale. Both elements mesmerised the mind of the young Kelsen and left an enduring mark that is today worth revisiting and contextualising to recover his first steps as a political and legal theorist.