Answer
There are several men in the New Testament referred to as “Herod.” These Herods were part of a dynasty, a partly hereditary, partly appointed line of Idumean rulers over Israel during the days of the Roman Empire. Unlike other previous kings of Israel, the Herods were appointed by the Roman emperors and the senate.
The first of the Herods is often known as “Herod the Great” and is the one who sought to kill Jesus in Matthew 2 by slaughtering all the infant boys. This Herod also tried to enlist the wise men to reveal the whereabouts of the baby Jesus. According to Jewish historians, this first Herod, also called Herod the Ascalonite, was the son of Antipater, a friend and deputy of King Hyrcanus. He was made king in the room of Hyrcanus his master by the senate of Rome.
The son of Herod the Great was Herod Antipas (or Antipater), who was referred to as Herod the tetrarch (Matthew 14:1; Luke 3:1). The word tetrarch signifies that one who governs a fourth part of a kingdom. His father Herod the Great divided his large kingdom into four parts and bequeathed them to his sons, an action confirmed by the Roman senate. This Herod Antipas was tetrarch of Galilee, the part of the kingdom assigned to him. He is the one Jesus was sent to during His trials and eventual crucifixion (Luke 23). This same Herod Antipas was the Herod who had John the Baptist murdered (Matthew 14).
Herod Agrippa I was the grandson of Herod the Great (Acts 12). It was he who persecuted the church in Jerusalem and had the apostle James, the brother of John and son of Zebedee, put to death by the sword. By the hand of Herod Agrippa I, James became the first apostle to be martyred. Two of Agrippa I’s daughters were Bernice and Drusilla, mentioned in Acts 24 and Acts 25.
Agrippa’s son, Herod Agrippa II, was instrumental in saving Paul from being tried and imprisoned in Jerusalem by the Jews who hated his testimony of Jesus as the Messiah. King Agrippa, out of consideration for Paul being a Roman citizen, allowed Paul to defend himself, thereby giving Paul the opportunity to preach the gospel to all who were assembled (Acts 25—26). Agrippa II was the last of the line of Herods. After him, the family fell out of favor with Rome.