This portal is the outcome of an international research project carried out in the centennial of the Treaty of Rapallo between Italy and the Kingdom of Serbs, Croats and Slovenes (1920-2020). The website gathers all the archive material found between Italy, Slovenia, Croatia and Serbia that is pertinent to the Treaty, in order to make it available to the broader academic community and to the general public. More material will be added in time from other archives and contributors. The portal is a project by Unione degli Istriani – Libera Provincia dell’Istria in Esilio with the support of the Italian government, Regione Autonoma Friuli Venezia Giulia, Università Popolare di Trieste and Alma Mater Studiorum University of Bologna.