Drawing on Slovene, Croatian and Austrian archival sources, the article sheds light on lesser known facts regard-ing the role that officers of the former Habsburg Army played in the diplomatic negotiations over the Yugoslav borders at the Paris Peace Conference in 1919. In respect of those whom historical circumstances turned into supporters of the new state’s diplomatic endeavours, the article brings forth the texts of three military officers: Svetozar Boroević de Bojna, Slavko Kvaternik, and Rudolf Maister