Now in the fifteenth year of the reign of Tiberius Caesar, Pontius Pilate being governor of Judea, and Herod being tetrarch of Galilee, and his brother Philip tetrarch of the region of Ituraea and Trachonitis, and Lysanias tetrarch of Abilene,
The fifteenth year of the reign of Tiberius ...  On Sept. 17,14 A.D., this ruler ascended the throne of the Roman Empire.[1]; Luke 3:23 of this chapter states that Jesus, very near this time, was "about thirty years of age."  This was the consideration that led to the mistake in our present calendar of dating Jesus' birth at the beginning of our era in the year 1. It is now known, however, that Tiberius was reigning at the beginning of the year 11 A.D. The Encyclopedia Britannica has this: