The first of the Popillii to obtain the consulship was Marcus Popillius Laenas in 359 BC, only eight years after the lex Licinia Sextia opened that magistracy to the plebeians.
[2] The chief praenomina of the Popillii were Marcus, Gaius, and Publius, all of which were among the most common names at all periods of Roman history.
The only distinct family of the Popillii mentioned during the Republic bore the surname Laenas, cloaked.
[3] Cicero describes the incident believed to have given rise to the cognomen: Marcus Popillius, the Flamen Carmentalis, was performing a public sacrifice in his sacerdotal cloak, or laena, when he learned of a riot occasioned by strife between the plebeians and the patrician nobility.
[4] His descendants seem not to have shared his disposition; as the historian William Ihne put it, "the family of the Laenates was unfavourably distinguished even among the Romans for their sternness, cruelty, and haughtiness of character."