Easton's Bible Dictionary

Augustus - the cognomen of the first Roman emperor, C. Julius Caesar Octavianus, during whose reign Christ was born (Luke 2:1). His decree that "all the world should be taxed" was the divinely ordered occasion of Jesus' being born, according to prophecy (Micah 5:2), in Bethlehem. This name being simply a title meaning "majesty" or "venerable," first given to him by the senate (B.C. 27), was borne by succeeding emperors. Before his death (A.D. 14) he associated Tiberius with him in the empire (Luke 3:1), by whom he was succeeded.