Controversial Šibenik native Ivan Tomko Mrnavić (1580-1637) in his extensive literary and historiographic first book De Illyrico Caesaribusque Illyricis, which is extant only in MS (and which was created mainly between 1603 and 1607), in Latin, in seven books, describes Illyria (covering the provinces of Scythia, Thrace, Macedonia, Dardania, Thessaly, Epirus, Dacia, Dalmatia and Pannonia) and gives biographies of emperors of Illyrian origin. Two transcriptions of the MS have been found: one in the National and University Library in Zagreb, and the other in the National Museum in Sarajevo, which are practically identical in content. The third example of an MS, from the Convent of the Minorites in Dubrovnik, is an extensive compendium that, probably, was drawn up by Mrnavić’s good friend Rafael Levaković. In theme and substances similar to the much more celebrated work Il Regno degli Slavi of the Dubrovnik Benedictine Mauro Orbini (they were created more or less at the same time), Mrnavić’s work, in practically all its characteristics, fits into the tradition of Croatian Baroque Slavism. But unlike Orbini, Mrnavić often quotes Croatian authors, among them Marko Marulić, whom he particularly admired. In this study, all the references to Marulić in the manuscript are given, and in particular the parts of the Mrnavić text in which there are quotes or paraphrases of some of Marulić’s writings are analysed. These are the texts In epigrammata priscorum commentarius and Regum Dalmatię et Croatię gesta, both printed for the first time in the Lučić work De regno Dalmatiae et Croatiae 1666, and so it is clear that Mrnavić must have known MS versions of them. Also quoted are the remain works in which Mrnavić quotes or mentions Marulić. Quite obviously, Mrnavić valued Marulić very highly, as shown by the fact that he called him the second Jerome, which was often referred to by later authors.