 Several members of the Julio-Claudian dynasty exchanged their original praenomina for cognomina, or received cognomina in place of praenomina at birth.An emperor might emancipate or enfranchise large groups of people at once, all of whom would automatically receive the emperor's praenomen and nomen.Yet another common practice beginning in the first century AD was to give multiple sons the same praenomen, and distinguish them using different cognomina; by the second century this was becoming the rule, rather than the exception.