The author analyzes the late medieval Trogir nobility in the period between 1280 and 1420 through the prism of the activities of political factions. Following the anthropological and comparative-historical literature, the paper identifies political factions composed of nobles, commoners and other actors of Trogir's social and political life in the period under consideration, which competed for political power within the then Trogir political community. Political competition often resulted in the escalation of ever-present and latent social conflicts into open factional conflicts. The escalations were directly conditioned by geopolitical changes within the Hungarian-Croatian Kingdom or Venice, on the one hand, or by political relations between the Hungarian ruler or representatives of the Hungarian royal government in Croatia and Venice itself on the other hand. In this context, Trogir's political actors should also be understood as the periphery of wider social networks headed by powerful actors or structures within the Kingdom of Hungary or the Venetian Republic. However, although the “global” political context has accelerated and radicalized political dynamics at the “local” level, the content of that same dynamic is the fruit of social and political relations within the local elite itself. The political conflicts in Trogir took place simultaneously with the process of the shaping of political institutions, which was particularly intense in the late 13th and early 14th centuries. Or more precisely, political conflicts actually directly influenced the structural and normative formation of the political community during the 14th century, especially until the 1360s, when the city's General Council (generale consilium) began to be formally called the Noble Council (generale consilium consilium nobilium uirorum). The paper will focus on three situations of open factional conflicts, namely in the periods 1310 - 1328, 1357 - 1358 and 1386/1387 - 1395, i.e. the context of the Venetian-Hungarian war and its consequences for political relations within Trogir (1409 - 1420). Violent episodes often leave behind more preserved information, but their significance should not be overestimated and therefore efforts were made to pay as much attention as possible to other periods and traces of latent conflicts, and finally to see open and latent conflicts in the wider context of Trogir's political arena, which was largely in statu nascendi during the period under review. The role which the Trogir Canons played in the political events is emphasized as a explicit example of an latent conflict that was directly connected to the quarreling political conflicts. This example also showed the real (and potential) extent of the factional grip. Accordingly, the author sought to identify in detail and prosopographically reconstruct factional actors in all periods of crisis. In the broader chronological context, the factors of continuity (noble factional core), i.e. discontinuity (periphery of the faction and aristocratic clientele, as well as political loyalty of Trogir factions at a given time) are clearly distinguished. In order to perform prosopographic analysis, it was necessary to consider the key connecting elements in the formation of factions, namely patron-client relations, family and marital ties, business cooperation and friendships. However, the key factor is the personal relationship of factional actors with the factional leader, who could act either as a "patron" (from a position of greater social power and influence) or as a "broker" (from a position of limited social power based on the leader's ability to mediate within a heterogeneous political coalition). Throughout the entire dissertation, the author utilizes relevant and specialized historical research as those of Jacques Heers or Patrick Lantschner, among many others, which deal with political factions in the medieval West. The Dalmatian-Croatian case of Trogir represented itself as an excellent and grateful example for a thorough analysis of political factions in a Dalmatian City, modelled upon the aforementioned historians and many other historical monographs which are mentioned in more detail in the main text of the dissertation.