The family produced several distinguished generals, and towards the end of the Republic, the Domitii were looked upon as one of the most illustrious gentes.
During the time of the Republic, there are recorded only two branches of this gens, the Ahenobarbi and Calvini, and with the exception of a few unknown personages mentioned in isolated passages of Cicero, there is none without a cognomen.
[1] Calvinus, the name of the oldest family of the Domitii, is derived from the Latin adjective calvus, meaning "bald."
The lengthened form, Calvinus is a diminutive, generally translated as "baldish", although it could also refer to the descendants of someone who had borne the surname Calvus.
To explain this name, which signifies, "Red-Beard" (literally, "Bronze-Beard"), and to assign a high antiquity to their family, it was said that the Dioscuri announced to one of their ancestors the victory of the Romans over the Latins at Lake Regillus (498 BC), and, to confirm the truth of what they said, that they stroked his black hair and beard, which immediately became red.