Herod the tetrarch - See also Mark 6:14-16; Luke 9:7-9. This was a son of Herod the Great. Herod the Great died probably in the first year after the birth of Christ, and left his kingdom to his three sons, of whom this “Herod Antipas” was one. He ruled over Galilee and Perea. See the notes at Matthew 2:15. The title “tetrarch” literally denotes one who rules over a “fourth” part of any country. It came, however, to signify the governor or ruler of any province subject to the Roman emperor - Robinson, Lexicon.
Heard of the fame of Jesus - Jesus had been a considerable time engaged in the work of the ministry, and it may seem remarkable that he had not before heard of him. Herod might, however, have been absent on some expedition to a remote part of the country. It is to be remembered, also, that he was a man of much dissoluteness of morals, and that he paid little attention to the affairs of the people. He might have heard of Jesus before, but it had not arrested his attention. He did not think it a matter worthy of much regard.