from
Easton's 1897 Bible Dictionary
Tiberius Caesar
i.e., as known in Roman history, Tiberius Claudius Nero, only
mentioned in Luke 3:1. He was the stepson of Augustus, whom he
succeeded on the throne, A.D. 14. He was noted for his vicious
and infamous life. In the fifteenth year of his reign John the
Baptist entered on his public ministry, and under him also our
Lord taught and suffered. He died A.D. 37. He is frequently
referred to simply as "Caesar" (Matt. 22:17, 21; Mark 12:14, 16,
17; Luke 20:22, 24, 25; 23:2; John 19:12, 15).