Gaius Rabirius Postumus was a son of Gaius Rabirius who was defended by Cicero in 63 BCE. He was also one of the Romans who borrowed money to Ptolemy Auletes to help him in restoring his rule over Egypt.
Later when Aulus Gabinius – who was convinced to do it by Pompey – marched on Egypt and secured the throne for Auletes Postumus became his minister of finances. After a year poeple of Alexadnria imprisoned both Auletes and Gabinius for their incompetence. The latter managed to escape to Rome where in 54 BCE he was accused of participation in illegal invasion. He was also accused of planing to bribe people of Rome with his accumulated wealth. Rabirius denied all accusations but testimonies of Egyptian witnesses proved that he was lying. He was defended by Cicero who managed to secure acquittal for Rabirius by securing the sympahy of some judges.