This chapter discusses the inaugural dissertation of the first ex officio professor of natural law in Denmark, Andreas Hojer: the 1735 Dissertatio iuris publici universalis de eo quod iure belli licet in minores. In doing so it seeks to shed light on a little known figure in the early Danish enlightenment, albeit one who was very influential in his day. It explains why Hojer chose what on the face of it seems a minor topic of the law of nations, by discussing the dissertation against the political and polemical background of Denmark-Norway’s participation in the Great Northern War. It is argued that Hojer’s dissertation illustrate the need for academic expertise in defending the political interests of the Danish absolute monarchs, particularly against the Dukes of Holstein-Gottorp to the south, and that this concern was instrumental to Hojer’s appointment. While Hojer endeavored to fulfill this role, his dissertation also revealed an interest in drawing out the full consequences of the conceptual framework of natural law, an interest that was unique, and controversial, in the intellectual context of early eighteenth century Copenhagen.