<p>Mythistoric genealogies, the claims of divine or heroic ancestry made by the Roman elite during the Republic, provide an alternative lens through which to understand social constructs and political experiences of Romans. However, the relationship between mos maiorum and these mythistoric genealogies remains unexplored in modern scholarship in a detailed and focused manner. This research sets out to demonstrate that mythistoric genealogies were a natural evolution of the Romans’ ancestral veneration which is implicit in mos maiorum. This thesis focuses on three of the most politically prolific gentes whose social influence spanned the 500 years of the Republic. First, each case study assembles and analyses the evidence (numismatics, literature, sculpture and architecture) that preserved the claims made by each gens and arranges them in such a way as to furnish a linear account of the genealogies. Second, each case study presents and analyses a member of each gens to demonstrate how he exemplifies, retains, or emulates the attributes, instructions and morality of their described genealogy. The historical person is analysed through the lenses of mythistoric genealogy, Paradigmatic Pressure, and Social Capital. The three case studies demonstrate that the clans of Aemilius, Fabius, and Valerius used their mythistoric genealogies to anchor themselves to the majesty of Rome’s past and that mythistoric genealogy was an integral part of mos maiorum. Furthermore, the connection of mythistoric genealogy, as an evolved element of mos maiorum, is emphasised through the following factors: they serve an educational function; serve as binding instructions; display the retention of events, lives and deeds of heroes; serve as examples meant for the emulation of the past morality; and, finally, can be shaped and reconstructed to suit present situations or political agendas. The results of this research contributes directly to the ongoing discussion of mos maiorum, discusses the social concepts held by elite Romans during the Republic, demonstrates how inter-generational connections were crucial to ideals held by the nobiles, and engages with mos maiorum in-depth (in terms of myth and legend) in a way that has not been done in a ‘per gens’ manner in scholarship, filling a gap in the study of social history during the Republic.</p>