Vedius Pollio's first certain appearance in historical sources comes after Octavian (later Augustus) became sole ruler of the Roman world in 31 BC; at some point Vedius held authority in the province of Asia on behalf of the emperor.[4] For a mere equestrian to govern this province was anomalous, and there were presumably special circumstances; Vedius' term of office could have been in 31–30 BC before the appointment of a regular proconsular governor, or after a major earthquake in 27 BC.[5] He later returned to Rome, and when Alexander and Aristobulus, the sons of Herod the Great, came to the city in about 22 BC, they may have stayed with him.[6]