("proconsul" or "propraetor"); Greek anthupatos . The supreme governor of the provinces left by the emperors, still under the Roman senate (Acts 13:7; Acts 19:38, plural for singular). The emperor gave the peaceable provinces to the senate. Over these the senate appointed those who had been praetors; governing only one year; having no power of life and death, not wearing sword or military costume (Dion. Cass., 53:13-14).
Achaia had been imperial, governed by a procurator, but was restored to the senate by Claudius (Tacitus, Annals 1:76; Suet., Claud., 25). So Gallio is rightly named "proconsul" or "deputy" (Acts 18:12). Cyprus after the battle of Actium was an imperial province (Dion. Cuss., 53:12), but five years later was given to the senate and had a deputy; so, Acts 13:7-8; Acts 13:12 is accurate. A coin of Ephesus, in the senate's province of Asia, illustrates the use of "deputies" in Acts 19:38.