“John had rebuked

Herod,

The tetrarch ruler,

Because of Herodias,

His brother’s wife.

John also rebuked

Herod

For all the other evil things

That he had done.

Herod added

To all these evil things,

When he locked up

John in prison.”

ὁ δὲ Ἡρῴδης ὁ τετραάρχης, ἐλεγχόμενος ὑπ’ αὐτοῦ περὶ Ἡρῳδιάδος τῆς γυναικὸς τοῦ ἀδελφοῦ αὐτοῦ καὶ περὶ πάντων ὧν ἐποίησεν πονηρῶν ὁ Ἡρῴδης,

προσέθηκεν καὶ τοῦτο ἐπὶ πᾶσιν, κατέκλεισεν τὸν Ἰωάνην ἐν φυλακῇ

Both Mark, chapter 6:14-17, and Matthew, chapter 14:1-5, have the imprisonment of John much later in their works, while Luke has it right here at the beginning of his gospel story.  Luke said that John had rebuked Herod Antipas, the tetrarch (ὁ δὲ Ἡρῴδης ὁ τετραάρχης, ἐλεγχόμενος ὑπ’ αὐτοῦ) of Galilee because of Herodias (περὶ Ἡρῳδιάδος), his brother’s wife (τῆς γυναικὸς τοῦ ἀδελφοῦ αὐτοῦ) and all the other evil things that Herod had done (καὶ περὶ πάντων ὧν ἐποίησεν πονηρῶν ὁ Ἡρῴδης,).  Herod added to all these evil things (προσέθηκεν καὶ τοῦτο ἐπὶ πᾶσιν), when he locked up John in prison (κατέκλεισεν τὸν Ἰωάνην ἐν φυλακῇ).  The Roman educated Herod, was the ruler or tetrarch of Galilee and Perea from 4 BCE-39 CE, as a client region, in the Roman Empire.  This Herod Antipas was the son of Herod the Great.  He had built the capital city of Galilee Tiberias, since he was a favorite of the Roman Emperor Tiberius (14-37 CE).  Herod, the Roman ruler in Galilee seized John the Baptist and put him in jail.  John had been complaining that Herod Antipas had married the wife of his half-brother Philip, after he had divorced his first wife.  His first wife went back to her father and started a war with Herod Antipas.  Herod’s new wife was called Herodias.  John had called him out for this marriage with Herodias, his brother’s recently divorced wife.  John had told Herod that it was not lawful for him to have her as his wife.  Thus, Herod had John arrested and sent to prison.