The publication concerns the documents of the “Leonardo 39. Study Day” The construction of a myth “that isheld at the Museum on 18 January 2018, in collaboration with the University of Bologna. The conference isIt was dedicated to the Leonardo da Vinci Exhibition and the Italian Inventions organized in Milan in 1939, oneof the most important cultural events conceived around the figure of the winning artist. In full climate ofautarky from the exhibition emerged the ideological matrix of Leonardo’s presentation as an inventor andthe ancestor of an Italic technical tradition destined to stand on other peoples, a reading he hadlasting influence on historiographical studies following the fall of fascism, consecrating Leonardo asuniversal genius.The aim of the conference was to define the outlines of the historiography of Leonardo that cameforging in the Leonardesque Exhibition of 1939 and to unveil the ideological mechanisms promoted by the regime in thedefinition of broad cultural propaganda events.In the proceedings the contributions of the participants to the sessions will appear: Marco Beretta – University of Bologna;Alessandro Tosi – University of Pisa; Francesco Cassata – University of Genoa; Elena Canadelli – University ofPadua; Claudio Giorgione – Leonardo da Vinci National Science and Technology Museum; Roberto Cara -Art historian; Monica Azzolini – University of Bologna; Andrea Bernardoni – Museo Galileo of Florence;Davide Colombo – University of Parma; Yoshimi Takuwa – University of Kobe.