Abstract: (“The Discovery of Transylvania” by the scholar Luigi Ferdinando Marsigli and his Italian collaborators in the Habsburg army) Count Marsigli is a personality of the Italian academic world (celebrity acquired during his lifetime), of noble Bolognese origins who also served as a officer in the christian-mercenary armies of Emperor Leopold I of Habsburg in the "Great War against the Turks" (1683-1699). With his encyclopedic-enlightenment researck skills, the passionate explorer makes a consistent contribution to the knowledge by the Viennese Aulic Council of the new possessions acquired by the war from the Turks in various fields of earth sciences (geography, geology, biology, mineralogy, hydrology) and also (history, demography, theology, political science), thus helping the House of Austria to take the best decisions in the administration of these new prossesions: Hungary, Transylvania, Banat of Timisoara, Serbia, Bosnia and Croatia. Being since the end of the 17th century a member of several important academic societies in Rome, Paris and London, Luigi Ferdinando Marsigli publishes his research at a high scientific level in two editions in Latin and French in Hague (in 1726 and 1744), in 6 volumes, the conclusions of his work. For the topic of the colloquium, we believe that Marsigli's linguistic and ethnographic observations related to these populations deserve special attention, his records being, in our opinion, extremely valuable, capturing the languages spoken in Transylvania at the end of the 17th century, in their authentic and archaic form that allow today's researchers to judge how this multilingual and multicultural environment has been able to preserve itself until now.