Marcus Petronius Mamertinus, possibly known as Sextus Petronius Mamertinus, was a Roman senator originally of the Equestrian order. He served as suffect consul in 150 AD as the colleague of Marcus Cassius Apollinaris.[1]
Edward Champlin has argued that Petronius Mamertinus is a kinsman of the orator Fronto, based on a letter Fronto wrote to Petronius, commending a young man to him, in which Fronto addresses Petronius as a member of "our familia".[2] Champlin writes, "There can be no doubt that here, as elsewhere, familia means precisely family to Fronto."[3] Anthony Birley notes this supports his earlier argument that Petronius had an African origin, and further argues that his postulated wife, Septimia, was a cousin of the future emperor Septimius Severus.[4] On the other hand, Géza Alföldy suggested Petronius had an Italian background, where the cognomen Mamertinus is most common.[5]