In 27 B.C.E., Emperor Augustus of Rome took charge of all provinces requiring the presence of military forces, leaving ten others as senatorial provinces. The administration of the latter was carried out through proconsuls. The proconsuls were of two classes: Ex-consuls (those who had already attained the rank of consul), who were sent to the provinces of Asia and Africa (where a legionary force was maintained), and ex-praetors, sent to the other senatorial provinces.
It was the proconsul’s responsibility to direct the civil affairs of the province, make judicial decisions and maintain law and order. His jurisdiction was supreme in the province, although his actions were subject to review by the Roman senate. The collection of revenues was under a quaestor. The proconsul did not wear military dress or carry a sword.
The proconsul Sergius Paulus is mentioned at Acts 13:7, 12 as one who became a Christian. He was the proconsul of Cyprus. At Acts 18:12, Gallio is mentioned as being proconsul of the province of Achaia. Luke is accurate in using the term “proconsul” in these cases, for Achaia had been constituted a senatorial province in 16 C.E., and Cyprus by Emperor Claudius, who ruled 41-54 C.E. A Cyprian coin has been found with the head and title of Claudius (in Latin) on the obverse side and “Under Arminius Proclus, Proconsul of the Cyprians” (in Greek) on the reverse side.