 Particularly in the early Republic, the gens functioned as a state within the state, observing its own sacred rites, and establishing private laws, which were binding on its members, although not on the community as a whole.The cognomen, the third element of the "tria nomina", began as an additional personal name.It was not unique to Rome, but Rome was where the cognomen flourished, as the development of the gens and the gradual decline of the praenomen as a useful means of distinguishing between individuals made the cognomen a useful means of identifying both individuals and whole branches of Rome's leading families.