The Harmony Of The Gospels by St. Augustine
Chapter VII.--Of the Two Herods.
20. But with respect to the mention of Herod, it is well understood that some are apt to be influenced by the circumstance that Luke has told us how, in the days of John's baptizing, and at the time when the Lord, being then a grown man, was also baptized, Herod was tetrarch of Galilee; whereas Matthew tells us that the boy Jesus returned from Egypt after the death of Herod. Now these two accounts cannot both be true, unless we may also suppose that there were two different Herods. But as no one can fail to be aware that this is a perfectly possible case, what must be the blindness in which those persons pursue their mad follies, who are so quick to launch false charges against the truth of the Gospels; and how miserably inconsiderate must they be, not to reflect that two men may have been called by the same name? Yet this is a thing of which examples abound on all sides. For this latter Herod is understood to have been the son of the former Herod: just as Archelaus also was, whom Matthew states to have succeeded to the throne of Judæa on the death of his father; and as Philip was, who is introduced by Luke as the brother of Herod the tetrarch, and as himself tetrarch of Ituræa. For the Herod who sought the life of the child Christ was king; whereas this other Herod, his son, was not called king, but tetrarch, which is a Greek word, signifying etymologically one set over the fourth part of a kingdom.