Mos maiorum

The mos maiorum (Classical Latin: [ˈmoːs majˈjoːrʊ̃]; "ancestral custom"^[1] or "way of the ancestors"; pl.: mores, cf. English "mores"; maiorum is the genitive plural of "greater" or "elder") is the unwritten code from which the ancient Romans derived their social norms. It is the core concept of Roman traditionalism,^[2] distinguished from but in dynamic complement to written law. The mos maiorum was collectively the time-honoured principles, behavioural models, and social practices that affected private, political, and military life in ancient Rome.^[3]