His paternal grandparents were Aulus Larcius Gallus, a member of the equestrian class, and Sulpicia Telero, a daughter of the aristocracy of Crete.
Due to an inscription erected in Timgad in current-day Algeria by a civic council commemorating his status as town patron, we know his career up to the point he held the consulate.
[2] Priscus set up a dedication to Jupiter Optimus Maximus a few years earlier at Foum-Meriel, also in Algeria, which helps to determine the sequence of some of his offices.
Writing to his friend about the short reign of the emperor Nerva, Pliny the Younger alludes to alarmed reports concerning a man in charge of a massive army in the eastern part of the empire.
[7] Priscus' predecessor as governor of Syria was Marcus Cornelius Nigrinus Curiatius Maternus, an experienced general who had won victories for Domitian in his Dacian Wars, who disappears from history at this point.
He held the next two republican magistracies, plebeian tribune and praetor, then served as legate to the proconsular governor of Hispania Baetica.
[12] Anthony Birley speculates, on the basis of grammatical mistakes in one of his inscriptions, that Priscus' poor literacy limited his advancement.
[13] Although the name of his wife is not known, Aulus Larcius Lepidus Plarianus, a suffect consul at some point in the third quarter of the second century, is commonly considered to have been either Priscus' son or grandson.