The transformative processes within the Roman Empire during the late 3rd and early 4th centuries brought about significant changes across various aspects of societal life, including the educational sphere. The proliferation of Christianity played a pivotal role in reshaping existing pedagogical prac-tices, ideologies, and standards, particularly among the elite class. With the emergence of a new political landscape during the dominatum era, there arose a demand for revised didactic norms. These norms aimed to provide administrators and officials with comprehensive insights into the history of Rome, its allies, and adversaries. During the 360s, concise didactic guides or “Breviaries” were developed. Notable among them is Flavius Eutropius' “Breviarium ab Urbe condita” (“Breviary from the Founding of the City”), recognized as a prominent textbook on Late Antiquity history in contempo-rary scholarship. Another significant work is the “Breviarium rerum ges-tarum populi Romani” (“Breviary of the Deeds of the Roman People”), compiled by an individual known as Festus (? – ca. 380). However, this text remained on the fringes of scholarly discourse for some time due to its brev-ity and the author’s heavy reliance on predecessors. Most scholars agree that Festus' "Breviarium" serves as a didactic compendium intended for both the emperor, who may not have been highly educated, and the officials of his empire. While there is little doubt among researchers regarding the peda-gogical nature of this work, several other questions, such as those concern-ing Festus' sources and the degree of the author's independence, remain un-resolved in historiography. Currently, there exist two approaches to address-ing the issue of identifying and studying Festus' sources. The first, positivist approach (endorsed by R. Jacoby, E. Wölfflin, A. Bettendorff, D.V. Kareev), states that Festus' sources can be easily identified by comparing parallels between his texts and those of his predecessors. However, there are differing views within historiography regarding the number and composition of the sources used by Festus in creating the “Breviary.” The second, critical ap-proach (advocated by D. Büer), denies the possibility of compiling an ex-haustive list of the sources of the “Breviary” due to the limited tradition of creating texts of this genre that have reached us. This article examines the evolution of historians' judgments regarding the possibilities and methods of identifying and interpreting Festus' sources in the composition of the “Breviary,” as well as discussing methodological approaches to studying this work.