	While Postumius Varus was a third-century member of the "gens Postumii", he was not descended from the Republican family of the same name. According to Anthony Birley, he was the great-grandson of the orator Marcus Postumius Festus, a friend of the orator Fronto as a well as a fellow African; however Postumius Festus' descendants appear to have made Italy their home. Birley notes Postumius Varus had a brother or cousin, Titus Flavius Postumius Titianus (consul "ordinarius" 301), whose name implies a link with the family of the emperor Pertinax's wife, Flavia Titiana, although Birley admits "these names were common."