Herod Antipas was the ruler (tetrarch) of Galilee from the death of Herod the Great in 4 B.C. until his own death in 39 A.D. Still under overall Roman authority, he was given some measure of independence. Herod divorced his wife to marry Herodius, the wife of his brother Phillip. John the Baptist spoke out against this and was imprisoned and later executed by Herod. When Herod first heard about Jesus and his miracles, he thought it was John the Baptist come back to life. When Jesus was first brought before Pontius Pilate to be put on trial, Pilate sent him to Herod. Herod was pleased to see Jesus and asked Jesus for miracles, but Jesus would not respond. Herod then sent Jesus back to Pilate.
Similar to his father before him, Herod was not considered to truly be a Jew and was not loved by the Jewish people.
The Gospel of Mark mocks Herod by observing that Herod had trouble understanding the teachings of John the Baptist, and by derisively referring to supporters of Herod as "Herodians".
Historians generally conclude that the corrupt Roman emperor Caligula turned against Herod Antipas in the late 30s A.D. and forced his exile, soon after which he died of unknown causes.