The multitudes asked him, "What then must we do?"

 (i) Tiberius was the successor of Augustus and therefore the second of the Roman emperors. As early as A.D. 11 or 12 Augustus had made him his colleague in the imperial power but he did not become sole emperor until A.D. 14. The fifteenth year of his reign would therefore be A.D. 28-29. Luke begins by setting the emergence of John against a world background, the background of the Roman Empire. 