In Rome, Caesar Augustus is “Lord” (according to his subjects). In Jerusalem, Herod is “King of the Jews” (by title given by the Roman senate). In the Temple, the priests are awaiting the “Christ/Messiah” (or should be). So who would be the best candidate for a world-shattering announcement? For a king to be introduced? To whom should angels reveal the birth of the “king of the Jews,” who is “Christ the Lord?” 
Scripture: Luke 2:8-20