This was Herod the “Tetrarch” (“ruler of a quarter”), not Herod the Great. He was one of the sons of Herod the Great, and was better known as “Antipas.” After the death of Herod the Great, his sons went before Tiberius Caesar to plea their case for their father’s throne, for their kingdom was ultimately under Roman rule. Tiberius subdivided Herod’s kingdom into a tetrarchy and gave Antipas rule over Galilee and Perea. Herod Antipas later divorced his wife and took his brother’s (Herod Philip II) wife, Herodias, as his wife. She was not only his brother’s wife, but also his niece (“Herodias” was Herod the Great’s granddaughter). John the Baptist publicly rebuked Antipas for this sinful union. Antipas, perhaps fearing anarchy in his kingdom from John’s preaching, and at the urging of his wife and her daughter, imprisoned and later beheaded John. It was this Herod, Herod Antipas, that now feared that Jesus was in fact John the Baptist raised from the dead. The contrast between this puppet king of the Jews and the true king, Jesus, Son of David, Son of God is striking. Yet, the choice still remains today for us. Which king will you choose? The world’s puppet king or the One True King, Jesus?
See this chart to understand the family tree of “Herod the Tetrarch: